Okay guys, thank you for all coming all of the four of you. Um, welcome. So uh, it's that time of year. um I Got so many calls today about furnaces, just not lighting and issues. Um, because it was 87 degrees out there again today. so winter is getting kind of hard. but um yeah I mean Super relevant for us right? I mean last week it was in the 50s and I thought for a second winter was here. but I mean Winter's here for everybody else in this world so just wanted to welcome the rest of the country that's going to be watching this for the next 10 years. It's going to be that good. It's going to be up there at the top of the list on our classes. Welcome to this show! and I'm so glad you're here! And I'm sorry about winter. it's 86 degrees here, we're sweating, we're miserable. All right. This is our class furnace diagnostic sequence of operation. My goal is super practical class since none of you guys know me. I'm going to go ahead and get started with foreign first things first with any class. you guys need to get to know your instructor, know me for who I am here I am and um this is going to be a great great class. I'm excited. Uh, you guys can call me whatever you need to on here. Um, some people call me Bert that's fine too. but yeah I just want you to know the person you're dealing with be able to trust. Obviously it's not about me this class at all just but I've been through some things you know, seen some things and um, really I should just start at the beginning and just go with you where it started our journey and furnaces. So there's a lot of furnaces and Gainesville I was born in Gainesville 1989. So I am an 80s baby. As you can see, I'm literally an 80s baby. So uh, the next year? No. I'm just kidding. All right. All right, that was great. Nice. Okay, so today's class. um. sequence of operation: common diagnostic issues replacing felt part parts replacing failed Parts flame sensors checking gas pressure. All right. You ready for that? Yes, ready to keep it as practical as possible Now I Do have to say Brian did a class on this and some of you were there and it was way better so far right? But I mean he's um, yeah, I don't want to diss him or anything. he's the guy in that picture right there, but right here. But yeah, he's sometimes smarter than us and so that's not going to be the situation. Today we're going to talk about furnaces a couple different furnace designs here. Anybody ever seen a natural draft furnace in the field in Florida Mario has? well, uh, Jacob just was that working on one? uh, two days ago? Really? Yep, it was a failed Universal board in there. But yeah. interesting. So natural draft flame comes in and the actual heat rising up creates the vacuum that pulls in more air for combustion to the bottom. So there's no exhaust blower. Yeah, it's literally just Your Flames that create that cycle. So you have to have air available for combustion and then exhaust go up through your chimney pipe. So yep, uh, you will still find pool heaters pretty commonly like that. a pool heater that doesn't actually have a blower assembly. Um, so you guys will see those things. eighty percent. Uh. furnaces. The difference here is that we we still have open combustion. The bottom right in front of the furnace air has to be able to get in, but we're actually pulling that in through the inducer fan motor and um, and exhausting it out. And so still open combustion. But we have an induced draft controlled by a motor. It's safer, less can go wrong there. And um, there we go. And then 90 furnaces. Anybody seen a 90 furnace in? Central Florida Just me. and Sean It does create its own connotation. Yeah, yeah. and uh, the one that I saw just had a one pipe attached to it. just an exhaust pipe going up outside to the metal flute Pike from the previous furnace. It was so sketchy. But the difference here? It's closed combustion. So you bring air in through a seal chamber so you have your piping out to the external wall. You bring air in for combustion. You don't see the flame happen. it's all sealed. It's a lot more controlled and you're using ninety percent of the heat that you're burning and so you will. Actually, then you will exhaust. You'll Force the air out and it will actually be usually decently pretty cold because most of the heat is actually absorbed in the furnace and is going into your home. It's a very efficient system, but in that process of cold air coming in with moisture, there's condensation that happens there so you have like a drain set up. that has to be a part of this. But this is what most of the world up north is going to be dealing with commonly because it's just a lot more efficient way and we don't have a lot of those around here. So I'm spending most of my time today on here because today's class is about you guys and about us what we're going to be seeing in the next coming months and try to keep it as practical as possible. Okay, so on a furnace? Um, since we're mostly dealing with heat pumps around here, we have a few furnaces. What's the most important difference that a furnace has a heat pump doesn't? No, not the reversing valve. It is a difference. It's not the most important. They both have blowers. Come on. Joel You can say it. Fire. It's too obvious. I Said This is gonna be a really simple class. It has fire. That's right. Uh, so what do we need to create fire? That's what it is. Yep, we need fuel to rapidly oxidize fuel Fuel We need our fuel to. We need a source of heat for the fuel to First ignite right? Okay, so we got oxygen heat. fuel. Fire makes sense. Only reason I'm showing this is because think about the fact that this is that. Like for me, it's more extreme because I didn't grow up around it. We're heat pump country around here, but we're bringing fire into our houses and fuel and then we're pumping air in to burn it faster and hotter and more Clean. Like that's crazy. So furnaces are loaded with a bunch of safeties and that's where most of this class is going to be. Do We have to keep this fire from killing us. And so a furnace is loaded with a bunch of safety. So here's a furnace. Uh, picture that. Jessica Sent me the other day doing the maintenance on this furnace and I Just wanted to show you where our mixture of fuel, oxygen, ignition, heat source, and our gas in. So you can see here our gas comes in and then we have our heat. Source You see the glowing right here. That's our igniter. bright and red. She caught the picture right when it was glowing and and Flames quality stuff right here. And then you can see the flame down in here actually burning. That's our fuel. and here's our inducer blower. So this is hooked up to the chamber. Let me go back here a couple. You can see the blower hooked up to the heat exchanger chamber. So when it comes on, it's forcing air into that chamber, it's sealed and the flame comes into that chamber. and then um, the heat pushes the air out and it exhausts out through the top. Make sense, All right, Is that is that just a graphic with it back and forth? Yeah. so I'm going to be honest with you. this is just like a 3D graphic that somebody drew. This isn't real, but that's not what you were asking. Oh no, it. literally. the heat exchangers look like an S like half of the time. Okay, there are different designs, but yeah, that was. this is a very accurate looking graphic. I realized what you're asking. Yes, absolutely after mocking you I knew exactly what. Yeah, new guy. What? Furnace Expert? Much? Yeah, you can ask anything you want I probably have the answers. so points of interest. This is another slide about what our class is going to be right? But I made some slides and I got some help and I'm excited about it. So inducer fan motor and the flue pipe that exhaust the air and our airflow switch igniter, limit switches, gas valve, flame sensor, furnace board. We're going to talk about all of these first. Let's talk about what they do and we'll talk about how they go wrong. What's this inducer fan motor? Absolutely all right. So this motor is powered 120 volts right here. This is the back side, just just so you can watch it spin. You know it's moving and then you can grab it and slow it down if you want. That's hard on the motor and there's really no reason to do that good. Cut your finger so, but I'll show you later when the camera is off. Pulls in air for combustion, so this is important. We're pulling in air to actually help generate our fire. If we don't have enough air, then we're not going to be able to safely burn the Flames through the heat exchanger. We can have the potential flame rolling out like just the gas, building up and then lighting and rolling out right so and then. Also, you just need oxygen for fuel, so we got to have it. Um, and then I have pushes out exhaust air in quotation marks. This is the one nerd moment of my entire class. Even though it's pulling in air and like pushing through the heat exchanger by the time the air gets to the top of the heat exchanger. Like, by the time he gets out here the flame, the heat that has been mixed with the air is causing that to rise so quickly that it's actually under a negative pressure here. So if you've ever noticed, it's never like we're not making sure these are airtight watertight seals on a 80 furnace. 90 you have air in air out and it actually is pressurized because we don't have the hot air coming through here. but on this one it is hot. So there are, uh, different regulations in installing these like your gas pipes being close to here or anything. coming here they have you have to have a certain distance, um, or um, the type of piping. whether it's double wall or single wall. But the point is that I'm trying to make is the hot air is actually going out of here so fast it's creating a vacuum behind it. so if like, you poke a hole, it's sucking in air. All right. So and then um, just thought that was kind of cool so it doesn't actually push it. but I mean if there was no flame, it would be pushing the air out. But thank you thank you for hearing that Now the nerd moments in classes are great. That's what Brian's really good at and it makes it really interesting for people. I've been doing this for years. However, if I give you too many of those and I have them all like they're my head's just like this combustion. I'm not I just want you to remember what's practical that you're going to use tomorrow. That's it I promise and I won't talk about that anymore I'm done talking about it. Did it bother you that I talked about it I'm done. I'm done All right. So this is our airflow switch. is what I call it, but it's actually called a pressure switch. Typically, like manufacturers refer to it as a pressure switch. Why would I call it an airflow switch? Why would I call it an airflow switch? Please talk Joel You're not just the camera guy. Okay, you're here to learn. Oh, I'm sorry guys. I shouldn't yell at my camera guy. What was that? Okay, it's reacting to the air pressure. It's not measuring anything. but yeah. So apparently it's now measuring the air pressure. So it's reacting to air pressure. It proves that there's good air flow. It's normally open when there's no airflow and then it closes when it's pulled under a vacuum. Okay, so as the motor is running, it's and pushing air through this chamber. Uh, there's a vacuum where the air is coming in and the switch actually closes under that vacuum. And so it's much safer to have the switch hooked up to an area where there's a vacuum because if you had it hooked up to an area where there's pressure and this got blocked, the pressure. Would Still Force The switch close and so the system wouldn't know is blocked. So we have it hooked up on the vacuum side so that it will only pull in if enough air is moving by to create a vacuum. If enough air is actually so it's actual airflow switch, huh? Nice. That's not nerdy stuff because that's super practical. Normally closed. Do you may know what these switches are called? There we go limit switches they open on so they're normally closed. We have this whole Circuit of wires going through and the board's like is everything fine? Do I have the voltage that I'm sending out coming back Great! All the switches are closed. that means we're not too hot. Some have a manual reset on them, others automatically reset. They have the bi-metal inside so when it gets really hot it's like and then it cools down. So um, now our hot surface igniters our intermittent spark Ignition Direct Spark ignition. So this is the heat source that creates uh, that lights our fuel right. So just real quick on the differences in these hot surface is pretty much what everything is now pretty much like. That's the majority of what you're going to see. You have uh, like rude and ream They're still producing the uh direct spark ignition to where it just instantly. Sparks And so the gas valve opens, spark spark flame sensor. Make sure that it actually came on and so that would be the direct spark. You have the intermittent spark which you guys are going to still see on pool heaters. The intermittent spark has a tube coming in from our from our gas valve and connected straight to the gas valve. and so when it gets a call for heating it Sparks it feeds gas to that tube and then there's a little pilot flame that sits there on top of the flame sensor. If the flame sensor senses that we have a little flame, it knows that when it dumps gas, it's gonna light. If we have a small flame, it's going to light for sure. So before it even dumps gas, it proves Flame The design of that would be to be a little bit safer. So but yeah I don't need to go into what's actually more safe. Everybody's using Hot Surface Ignizer and igniters for the for the most part right now, so a few exceptions. you're still going to see the other ones. but yeah, um, your flame sensor also is your igniter. so there's a voltage sent down and it will actually jump across the flame sensor trying to get to ground. You'll actually have an arc come across there so a higher voltage. Those are frustrating to try to diagnose some pool heaters so they get so dirty and rusted out in that area. Okay, gas valve normally closed. That's important. The gas valve when it's not powered, is shut so we aren't dumping gas into the house. 24 volts is applied to the coil brings it on. Simple test. Am I getting 24 volts. Okay, it's not my board that's failed I'm actually getting 24 volts to this thing and it's not opening. it's my gas valve is filled. I'm jumping ahead. We're not getting the diagnostic part yet. Guys, please and keep the questions about why and how to diagnose it. Like for the diagnostic section, if we go all the way back to beginning, never mind. So drops gas pressure to the manifold. So the manifold is these burners down here and where the gas actually meets the the oxygen and the igniter. So it drops gas pressure. You need to have plenty of gas pressure coming in. It regulates it based on the manual adjustment, but you enter yourself. They always come from the manufacturer set for a certain parameter and then you adjust it if you need to. Flame sensor: By far the coolest element on any furnace for a tech mind is the flame sensor. Um, we're going to spend a little extra time on the flame sensor today. We have one that we're going to install that we're going to um, stock on our trucks flame sensors. um, are just literally a metal rod and the wire connected to your board. But they sit right in the in the flame. So if there's pollution in the air or a dirty flame like you don't have clean. Flame Or maybe somebody has got something on it in the past like touching it finger oils. It can corrode, it can start to break down, it can get dirty, and you have to clean it in order for electricity to pass through it. So again, that was Diagnostic and we're trying not to do that now. Flame sensing rod or flame rectifier. When the flame is present, a small current passes from the rod to ground via Flame. So literally electricity travels down here. It's hanging in the air. Then there's Flame. Electricity travels through the flame, right? That'd be a cool superpower. Can you imagine Travels through the flame to ground? right? Very cool. Small amount of current? It's not. It's not a great path. It's just like yeah. Go ahead. Joel Uh, the superpower would be the ability to travel through the flame to ground. Electricity can do that. Okay, the furnace board. Um, just pretend that's 3D. Like everything else, the furnace board receives commands from the thermostat, controls, furnace operation monitor, safeties, displays, error codes I Think you know what a board is. All right? Let's move on from that. All right. Most important part of this class will be for you guys to understand the sequence of operation right. If you don't know what it should be doing, how in the world do you know if it's doing that or not right? Like with anything sequence of operation. So all of your manufacturers you pull up the furnace and you read through Under the startup section they will have this detailed sequence of operation for their furnaces. Mwah, this is not one of those. This is one that uh HVAC school made. Okay, somebody take it from the top. I'll do it since I Have a mic furnace receives W Call wcall is our call for heat and furnace and a heat pump. W Call will be like our backup heat, but in a furnace we only have one. Heat W Call Furnish Receives it on the control board right here. 24 volts from the thermostat. The board confirms that our pressure switch is open. remember our pressure switch so it has to be closed in order for it to know it's safely running, but to ensure that it doesn't have a failed switch. It first confirms it's open and then close. So guys trying to diagnose a pressure switch will be like, let me just bypass this. It might be a failed twitch. Let me just test everything else. Bypass it. turn it on. No, the board's like way smarter than that. Nice drag. I'm not turning this on. Super dangerous. It needs to be open. Then our inducer fan comes on. so we're pulling that air and after the fan, it responds by closing because of the vacuum pressure. right? Uh, In this drawing, we have the board checks if the circuits are closed. The board actually always checks if the circuits are closed 24 7. it never stops checking. ever. Even if you have a power outage, it's checking if the circuits are closed. So you get a y call and the circuit's not closed. This is still going to come on as a safety. They're like oh crap, circuit's not closed. Something might be too hot. Let's just turn this on. Let's just sit here running. So it's not technically in the sequence of operation, but it's a pretty important element there. Um, Safeties Safety Circuit closed. The ignition sequence begins. If it's a hot surface igniter, they have a delay of like 30 seconds, usually a little less, but they have a delay to make sure it gets blazing hot before we dump gas onto it right. Whereas if it's in a spark ignition, a half second after the spark starts, the gas valve is going to open right where as if when it's not, you get you get the idea, Words and everything. Gas valve opens 24 volts gets applied to the gas valve from the board. It's like it's safe to dump gas in here. Boom Flame is proven. How is a flame proven? Uh-huh via via the flame Rod What a guy? Geez man, we need you over here. All right. come join us with this guy in a van. Um, Flame is proven through the flame. Rod So Within three seconds, less than three seconds, this thing clicks and there's no flame proven. Shuts out haircut so you will like immediately. the gas valve is going to close. air code: We don't have plane, we have gas No flame. I'm not dumping and then we go through a cycle where this pulls an air and exhausts any of the gas that has been dumped out but didn't Light, just pulls it through the system and exhausted outside. What's so confusing about that? Oh okay, you're just interested. That's your interested face. Okay, so it'll try three times and then go into a lockout and it's built to try three times because there can be weird, anomalyty phenomenal. Not I'm a nomenom of these. Um, where the gas coming in has air pockets. Maybe you haven't ran gas in half a year and there's some air pockets and so like it didn't immediately light? Yes, yeah, it does. Restarts all the way back to beginning. Other than your blower doesn't shut off and come back on. Yep, it'll reset all the way at the beginning. Whole sequence of operation. Um, yep. absolutely. like I said, Prove me wrong, anyone out there I Want you to just try your best? Hit Me With Your Best Shot It restarts at the beginning and we're about to show you that if it doesn't we'll just you can just edit that out. Blower starts all right. What blow are they talking about here? Yeah, so this is the air going into your house and coming from your house. And uh, there's a delay between flame and blower because manufacturers care about people if you're cold in your house and the blower kicks on right away. Cold air inside of all that duct work, sitting in your attic or under your house just getting blasted in. But if we could get this thing flaming hot and then hit it with air, that first gust of air is just like oh. I'm so glad. I Have a furnace and not a heat pump that let's look at a real sequence of operation. Oh I know this part. You guys join me. We're gonna turn on the furnace and um, we're gonna watch the sequence of operation in real life. Let's go first lesson in furnaces. because I don't want to ever hear about this from any of you this year. Okay, please turn on the heat someone anyone. Pedro What's wrong? No display. Let me just double check. I Have power. We do have power. Anybody anybody know that? That's my guy. YouTube Yeah, Turn it on. Look at this thing. Yeah, these doors will sometimes come loose. Um right after. Kalos does a maintenance like I Don't get it. It's weird. No, the customers will take these doors off to replace their filter. Yeah well. only on the side application. but a lot of our units in a garage. it's right under here. so the filter actually where this panel is. this panel goes mounts on the side filter side, right in. and then if they don't close their door up tight enough, it's just sitting there rattling and you got intermittent problems possibilities. But here's your switch. So you see the switch here. Door switch. We don't have power to our furnace. That's your first lesson. I Didn't make a slide for that. Okay, so yep, you want to, um, grab that drill real quick and let's just secure this other way. I was ahead of you. Dang it. without even looking, you're just like Boom Went for it. We have our call for heat, right? Cool, all right. And uh, what's going on over here? I'm actually an error code? Oh no. sure that's not part of the sequence of operation. How can you tell me That's right? So our long one arming our short one is our first letter and our second one is our first number. Thanks for correcting me on that because that could have got real confusing for everyone. They wouldn't have known what I was talking about. So number 12 let me just read it out. Blower on after power up when power is applied to the furnace, and there's a call for heat already because it just has a safety. You turn on power and there's already a call for heat just waiting. There sequence of operation: inducer fan motor comes on proves that there's suction through here. The switch closes. If the switch closes, they power. the igniter igniter gets hot. We have a bit of a delay and you have to turn on the propane tank. It is a common callback gas not turned on. Oh come on guys. Really, they come from the manufacturer in the opposition so we should like. every time it's 90 degrees outside, remember, turn it off or when winter comes around for our customers. You guys can check that out on maintenances or if you're an installer, you can just click the Switch Okay, there we go. There was our sequence of operation. Inducer fan motor came on. First the the board proved that the switch was open, then the inducer van motor comes on. They won't bring the fan on if the switch is closed. No, it actually will. It will bring the fan on and then pull the air clothed that the switch was closed before did not close or reopen. Let's just start at the beginning. proves that the switch is open after we get our call, and the thermostat proves that it's open, Motor comes on, proves that it's closed. Then igniter comes on and starts glowing. We have a delay. We've already proved our safeties are all closed. If one of our safeties were open I would shut it off. We have our delay and then the gas valve receives 24 volts. Gas valve opens and after that within the next three seconds, it has to prove with our flame sensing rod right here that you see just poked into the flame that there's a path and the current coming in to ground across the plates. All right. So what we're going to do is we're going to start this sequence of operation over with our first error code. Just uh oh yeah. So one of the limit switches I pulled which would simulate like a really hot surface. Right here. the limit switch will open. Tell that I've been back here. Yep. so everything just instantly shut off because one of our limit switch is open and it's going to restart because we're still getting a call for heat. Um, the fastest way to bypass its safety restart process is turn it off. Oops. that's cool mode. Can you switch it one more to off and then power back on? Foreign. So when it gets power and it's still in the opposition, give the board just a second. It won't do the the blower delay thing. Now we can go back to on. So I'd already noticed that the switch was, uh, closed. So when we do this, it's no longer pulling in. Then it should stop us and pull the air code for the switch being still open. So we're actually stopping it at the third step. First was the thermostat w second it proved it was open. Fourth step: The third step it brings on the motor four step. it proves that it's closed. All right. What's our error code anyone? Yep, so you want to read off 31 real quick. Just a description. First description. All right. Did not close or reopen. so it did close for a half second. but it reopened very quickly. We are back in service. It blew the squirrel straight out of the vent pipe and Boom! we no longer have an issue. So next it should be powering our igniter and that delay gets on. And um, let's go ahead and stop it. So it's still going to cost 24 volts and and call the relay. but this basically turns off our 24 volts from ever making it to the coil. This little switch right here. or you could have something from here down the line turned off at any customers home or gas outside turned off because they didn't pay their bills or something. Hate to hear it. You're gonna have to freeze money, don't grow on trees and I'm no Tree in or out of something like that. All right. So you notice that it went off and then came back on. We talked about this could be just a little gas in the lines. I mean a little air in the lines. It was just a little air in the line. See, we fooled the board like the board thought it was air. Yeah, he's glad he tried the second time. didn't give up. Yeah, so we have our lockout. When flame doesn't actually occur. Ignition proving Failure lock out which is uh, ignition lockout is actually 14. And then it tells you refer to Uh 34 where you can read why they think that might have happened. and as you can see a little flame rollout action here, we had to print out another diagnostic chart. Okay, there's your sequence of operation in person, live and in person with Bert So let's jump into Diagnostics This is going to be super practical. This is going to be your best friend or any furnace diagnostic issues. First thing I want to say about your common diagnosis diagnostic issues is you want to know what happened. So when you show up, don't just be resetting it. For instance, you just go straight to take this up open to look at your board. You reset power and you've lost your error code, right? So first things first. before you open anything up, look at your indicator light. It's going to be blinking. Whatever that last issue was and it even has a fault on there for a fuse. Like I said 24 volts missing. That's kind of cool. Okay, they did that on purpose. No Doubt Fuse is open yeah, so like low voltage short will be flashing. Even in cool mode, it's gonna Flash Super helpful. So don't reset your power. If you do reset your power, then you're going to be hanging out hoping to actually see what took place, that the problem is consistent enough you can address it and not just be like oops. it happened last night to you for some reason and I'll never know. So our common issues. Um, we'll come back to this chart as needed. We're going to start with our pressure switch not opening. Error code: Pressure switch not open. Error Code number 30 Oh, here we go: 31. Oh um, we have possible causes. not only what happened, but possible causes. If open longer than five minutes, inducer shuts off from 15 minutes before retrying. So Within that first five minutes, it's just going to keep running like I'm gonna keep trying and keep trying. Let's get these squirrels out of here these frogs out of here. Let's scare them out of the vent pipe. I'm just going to keep trying. And then after five minutes. Like all right, we haven't melted the snow covering the top of the flu pipe. we're done here. so it goes 15 minutes off for retrying so you could pull up in that 15 minutes. it's still going to be pulling your air code. Um, just the Pan's not gonna be running. Don't immediately condemn the motor when it's pulling the air code and you don't see the motor running just because normally you do see it running. there. We go All right. We've covered that proper vent sizing, not actually getting the right voltage to our motor. What would be the cause of that? Different causes. Amazing. That nice of them to list on here possible causes. and we can take a look into this so we're not getting our 120 volts to our motor. Then we're not. Actually, the board is what supplies that 124 volts right because the board has to check that everything else has done its job before it. Powers the motor. So the furnace board has 120 yen, but not coming out to the inducer fan motor at the right time of that sequence of operation. It's the board issue. Mm-hmm right? right voltage in not out board issue. Okay, inadequate combustion. Air Supply Super important. Let's take a look at the design of this. the outer panel. You ever wonder why these were on here. This needs to pull in air in order to have combustion. You need oxygen pulled in so this shuts. But it's not airtight so that it can keep pulling in air. This could be inside your garage. It could be inside your closet wherever it's at. There better be a source to outside air coming into that space. So you notice when you're working on furnaces in a closet, they will have like a vent in the ceiling going up into your attic or in the garage area. They will have holes cut out any external walls of the garage either down in the ground with screen over them or up top with the vent. Some way that when this is pulling in air, it's not creating a negative vacuum in a tight space. which could be a real problem. Um, there are some of those odd situations where you have a dryer and a furnace sharing the same like closet and everything's been shut. Somebody remodeled their home and they're like let's just close this in. It looks so ugly, right? and then it's like they're both just trying to suck in air to do their job. We get under negative pressure and we can't actually pull. The reason that that becomes so dangerous is because without the right amount of oxygen our our Flames not actually burning clean anymore and we're creating a lot more carbon monoxide in that situation. So that's one of the reasons it's so dangerous. You also have the possibility for flame rollout in that so inadequate air coming into the space can be the cause of that. So all of those things that we see here that could be a problem are going to be detected by this guy right here. We need to know how to test if this is doing its job. We need to know what it actually does. We got the error code. Let's check if we have a block vent pipe. Mud Daubers Classic Florida Am I right? Mud Dauber is filling that thing out. Don't get so crazy. They'll come down in here and they'll try to escape and they will literally clog this pipe. You'll just open it up and there'll be a wasp head like and you're like oh, that's weird. Pull it out. Another one right behind it, another one right behind it. They all like they all, um, they all hatch out of there, tried to crawl out and just clogged this pipe. Crazy stuff. Yeah, Take it out. Push a wire through a bunch of dried out dead floss. Good times. It could be all the way at the top, anywhere below and usually pretty easy to take this off and look up right? Um, or you just find a way. Okay, thanks. Also, if you take it off and you turn it back on before you actually are creating combustion, the air switch proves closed, then you've eliminated that. it's actually inside the pipe. You know what I mean you took it off and it's exhausting right here. Let's just not leave it off and and let the exhaust dump to wherever that space is or anything crazy like that. But you get you get what I'm saying here. Another possibility would be in the uh blower compartment where there's a wheel in there. so there could be something jammed in that wheel. Well uh. Jesus's first call we have a we have a video up on HVAC School Jesus's first furnace diagnostic call and in that call we found a frog caught in the wheel. A massive frog and there he was. dead in the wheel and we had to. We had to take him out of the wheel and we had to remove him from the space of the wheel in order for it to work. So yeah, yeah, up north they're much more common you have like squirrels and birds because they're literally trying to survive the cold right here. which is like tree frog lizard? Great. not nearly as awesome. raccoon Are you kidding me? Um, so yeah. So anything from the blower wheel all the way through the chamber blocking airflow. Let's pull that apart and let's check for that. If it is blocking the wheel, you're going to be seeing that this thing's not spinning right? Our motor is not actually spinning or it's going to be pulling crazy amps. Or it's going to be overheated, right? So that's a possibility. We could have a failed inducer fan motor, which we will talk about in the fail to inducer fan. We will not talk about that we're going to talk about right now. Failed inducer fan Blower: How do we test if our blowers failed? Yep, how many volts does it get 120 during the sequence of operation when it should have Voltage? Are we getting 120? We can also take an amp draw yeah to see if we're actually getting current passing through. we can touch the motor. Okay, it might be overheated now, but clearly it was dry, you know? Plus, it's hard. Like doing everything it can. Um, so then we're not like immediately assuming motor. In that situation, something's caused it to overheat. I Mean it can't overheat and fail too. But yeah. so voltage 120 to our inducer blower motor? Um, can it actually spin freely? Normal. lower diagnostic there. Let's go back to the we've covered the jam, blower wheel damaged, or a loose hose. especially on pool heaters where everything right here is outside this hose. the gas pool heater can be cracked so like trying to suck through a straw that like got kinked and cracked. Oh, so far it's not satisfying at all. No, well, this air switch is not satisfied either. so then they are pretty sensitive. Loose wires between here and the board. Not forget the obvious something disconnected. that's why it's not proving close. You could take the wires off and make sure it's actually close. Um I'll typically check for 24 volts here. make sure I still have it on the other side if I have it on both sides it's closed with passing through and coming back. Um, but it could be apparently like I put it on there a failed switch? Yeah, right eye rolling Emoji am I right we can, uh, actually check to make sure that we have um, a bat or under a vacuum like a minimum of 0.3 should pull in these switches. Uh, does anybody know how to use a manometer at all on any level? Great. Come up here, let's just do that real quick. Um, because if I get a call about I think this uh switch has failed and I'm gonna be like okay, what is the static pressure on the blower chamber? One of the easiest ways to find out if it's airflow or just like a mechanical switch failure or something else wiring? Go ahead Adriel push the zero so we've zeroed it out. Let's go ahead and turn it back on. You can wait for this. The AC guy turn the uh the fan on from Auto to on thinking he was turning on the system. So I'll never be upset at a customer again. Yep, what do we have? 0.6 Cool. That switch should be closed. Nice. Yeah, so that has proved we got airflow all the way through the system. So our issue is here switch or the possibility of a failed board. So I put that down here. at least likely even the switch is more common than the rest of this stuff here, right? But we got to go through that whole list and just think about what its function is and what it's trying to protect against. and then you can connect that to where you need to go next to find those issues. Water can get in them, especially on a 90 furnace. There's a lot more cold air and condensation going on in that airflow system. Water can get in them or you know you could just have a hurricane recently and Kyle called me today. He went to replace a furnace board it wasn't working in cool mode, wasn't bringing the blower on and uh, testing it in heat finds that the switch isn't working. unplug the hose and water just pours out so water can get into that system. so just keep that in mind. That's a thing that will cause can cause the floats that actually fails. That's where I was going with this moisture getting in there and then those metal components that are closing under the negative pressure. They're sitting here and then when there's negative pressure it's like now electricity can pass through. water is getting in that mix. Corroding? Yeah, water can't actually do that. limit lockout error code. All right. So typically if you walk up to a furnace and you actually have this error code, we have this switch right here. the resettable one which on this system is down here. little pop and this is located in the area where the flame will roll out if there's an issue with the flame and so if that one goes, they don't want that coming back on without a technician resetting it right. If you have flame rolling out, whereas these are on hot surfaces, this is connected to this pipe. We don't want that being too hot going through your uh, roof or whatever. Um, and then these other ones are connected to the actual this surface. So these are like surface area limit switches, but the one that is the flame rollout. We're on an older furnace or a pool heater. It will actually be like the white silicone with the fuse link that just burns up internally. Those situations that typically means you had way too much heat right there in an area where there should never be that kind of heat. and so you have to reset it manually. They want somebody on site investigating what happened. Whereas a situation where we have a limit switch open and it locked out because it happened. How many times does that need to happen? Limit Circuit Lockout at the limit draft Safeguard Flame roll-up vent GPS Open longer than three minutes. Okay, so it's not how many times it's longer than three minutes. So if it's open longer than three minutes which the second opens, it turns off and it still stays hot for longer than three minutes. Hot Enough to stay open, it's going to go into a lockout. Yeah, it recognizes. that's which. Yep, so the position. Yeah, it's a boardwalkout. Whereas when you saw me unplug it and put it back in right away. yeah, it was just like. all right. let's keep going. So customer has a dirty filter. The airflow coming across that heat exchanger is restricted. The heat exchanger gets a lot hotter than normal. The exhaust is hotter than normal. Either this one or the other one is open for longer than three minutes. We have a lockout, so you come back. You turn everything on. It runs great. No problem because it's just a just enough airflow restriction and it takes a run time certain amount of run time to get that hot. So first lesson of limit switches: If the switch is open, there's been an error code or it's failed. always ask the question what caused it and try to witness it recreate the problem. You're going to have to spend time if it's not happening again. Foreign, you just. you know. you tag it, Turn off the gas, move the customer out of the home run. That's a lie. Okay, uh. limit switches. Partially blocked flue pipe right here. so it's getting hotter than it should. but it's still enough airflow that this is engaging. but it's getting hotter than it can it should over time, so that could be part of it. You're going to need to be looking for those mud daubers at the top of the blue pipe or whatever. Um, that can create this problem. We have a flame rollout situation that I talked about. What could cause a flame rollout? Not enough oxygen. Great. so it's not cleanly burning so we have more field dumping in and we have oxygen to consume. the the fuel will kind of burn up. Maybe a gust of oxygen rolls in there that all just ignites. Yep, that's good. So we're going to make sure we have proper amount of air coming in. Another thing that could cause it would be air pockets in the gas valve. I Don't think so. no. uh. another thing could be the igniter. It's getting hot, but it's got a crack in it. It's not what it used to be. There's an issue going on with the igniter and so then the gas has repeatedly come on and off, and maybe that third time or so. A little bit more gas than typical. now. Usually on a furnace like this, manufacturers have the safeties to protect you from that. but you'll notice that your rollout's a lot more likely to happen on a pool heater. especially that since we run into more natural drafts, but much more likely to happen on something like a pool heater, they'll be sitting outside, there'll be a lot of wind just blasting into here and that can create a flame roll out. so then wrong gas pressures where it's not burning. clean. Um, could cause a flame rollout. There's a time that customer called and said the pool heater wasn't working and I show up and they're like yeah, it's not working. Uh, if you could just figure it out a couple young guys, you're pretty excited to have me there. but I don't know why they were so excited. So I Go out through the pool heater I'm just kind of looking around. I'm like some melted stuff here. You know the signs that maybe we had a roll out like just partial, but it's pool heater that can happen. you know, and look up and they're both just like their heads around the corner just watching. I'm like hi, you're like we're just watching. Turns out I'm like the third pool guy that they called out when it went to ignite it. Just boom right in front of my face. Seared my facial hair like my facial hair I was yelling at those guys they they're like her dad's not here but he told us to call people to check it out and you're the third guy, You can't figure it out I'm like you knew this was gonna happen. you didn't tell me I was so pissed yeah I disabled it I wrote All Over the inside of that heater like don't let somebody prank you again and did not offer to a solution for them. Just said you're gonna have to call somebody else I disabled it. multiple layers. Nobody's coming back. Not sure if it's legal to disable the heater here and a pool heater here in Florida but I did in that situation. Not gonna lie. Yeah, flame roll out. It's a real thing can happen. Loose wires again. Pool heaters. You guys are my pool heater people. The loose wires also can be corroded in. It's not loose, but it's been rusting. It's like breaking down and electricity is not passing through. It's actually literally starting to crack even though it looks like it's in place. So you've got a limit error code. It could be the wire issue, not just the limit switch. Let's think the whole picture. when this happens. like I said anything from clogged coil. We're not even using that, but our air is passing through dirty blower wheel filter. All those things are errors brought in to transfer heat. We need to actually the right amount of air to match how much heat we have in this furnace to keep everything cool enough that we're not opening our limit switches. So you are typically looking at airflow related stuff. and even if it's the airflow inside the flue pipe from the exhaust fan. Um, and then if it's a flame rollout, you're going to see signs, right? Your wires might be a little seared here. You might have some black down in here. If it's a flame rollout, that's scary. Use a lot of caution in trying to start that up. Try to figure out what might have happened before you go to turn something on right? Um, another thing that could cause a flame rollout would be like a gas valve failure where it's not closing down all the way. Um, so we have a little bit of gas build up. comes back on the light. Worst case scenario: I Mean let's not even talk about that. That would be that would be awful. Um, I'm going back to our gas valve slide because I don't actually have a gas valve diagnostic slide. So gas valve failure? How do we diagnose a failed gas valve? Anybody? Check the gas pressure? That's right. So this is one of the most misquoted things that I've noticed in our history. is that, um, well, everything else is working I Hear the gas valve trying, but it's just not opening. It's probably stuck. They do fail. So that's one of the reasons it's misquoted because you do find it failed and then I asked the question. Well, what were the gas pressures coming in and going out? Oh, I didn't check that? You have no idea if this thing's actually working if you haven't checked. Inlet Gas pressure is actually getting enough pressure to burn and then Outlet to prove that it's not actually passing through. Yeah, good. you're working on the gas package actual burner with quad as well just from being outside, so so it'd be allowing gas through anything to burn without lighting. Using the gas issue. Yeah, that's true. Yeah, so right on the little nipples that come out of the end of the burner, it's just a little tiny hole on those. They could be clogged or dirty, especially on a pool heater. Um, that's another thing that can cause flame roll out so where it's kind of dumping around the igniter and lighting a little bit late. Okay, so when you die, go to diagnosis. We want to make sure we got 24 volts in. We have pressure before our gas valve and no pressure coming out. Okay, so our pressure before our gas valve. For instance. if you're only just check your pressure before and you're not checking it when the gas pressure gas valve is supposed to open, you might have let's say just a little bit left in our propane tank. This customer has a propane heater on a pool heater. for instance. you might just have a little bit of gas pressure that's built up and it's enough that you're hitting your manufacturer specs on Inlet gas pressure. but the second it opens, that dumps through and that pressure goes down to zero. Where you should maintain midnight Inlet Gas Pressure: If the gas valves open, you should maintain that pressure that minimum pressure when it's open. so you can't just check. If you have it there, you have to check it. While it's trying to call and get everything set up, you restart your sequence of operation. You see the igniter glow red click. You hear the little tick tick. The 24 volt coil is trying to open that gas valve. Then you should see the pressure making its way through the valve. If it's a failed valve, you'll have good Inlet pressure. No pressure coming out of that valve so it could be stuck close. Yep, Oh great. Great question. So at the end of the class, we're actually going to go over measuring grass pressure with manometer. so use the manometer and they have ports there. Yep, that's part of class. So there's your gas valve diagnostic. Please No calls where we replace a gas valve and it just turns out the propane tank is empty. Please please, no calls be on pool heaters. Would people aren't actually using a furnace with propane tank? We're talking about pool heaters. Flame sensor. Okay, this is a uh, probably one of the number one reasons that we're out for a furnace issue is a flame sensing rod. So let's just talk about that. Reasons that you might pull the failure to prove ignition error code. It means that the board is taking it through the entire sequence of operation, even the gas valve opening. but within three seconds it has not proved any flame that has not been a current flow through that into the flame. So we have our error code and then if that happens, three times we have a lockout. Okay, so the gas valve could be stuck closed. We've talked about that. this is your error code for that. There's no like gas valve failed error code. It's we don't have plane error code. Sometimes the flame is burning fantastic and it still pulls the code. That's an issue with our flame sensor. We either have a board that is not um, sending voltage to the flame sensor or detecting it. We have a flame sensor that's damaged, could be cracked and starting to ground out inside the flame sensor because of this. uh uh. porcelain is cracked right here that's around the flame. Rod That keeps it from actually grounding out right? so it needs to not touch ground. You can't I've tried to jump right back in my young like first furnace like oh it goes, it needs ground. just dump it onto the ground. That's not good. that doesn't work at all. Yeah, it's a very small amount of current that should be passing through there. so if this is cracked and it's actually grounding out at the base of it, flame sensor or the flame sensor is dirty. If you look at it, it looks dirty. clean It so like something like steel wool or like an abrasive. uh, cleaning pad. like a little cleaning cloth that's just a little bit tougher. You can scrape it clean. There's this thing about dollar bills and the trade where people use dollar bills like and they get them clean and it works. So that's why you were told it does work. Apparently dollar bills also hold human oils and other potential dirty stuff that you get on there and it gets really hot. Maybe it hardens onto the flame sensor and over time corrodes it and damages it. So 20 times as good with a 20 bill. So take that tip. home. Manufacturer says right here: clean with steel wool and when I say right here I mean right there. Claim sensor must not be grounded. Uh, oxidized buildup on the flame sensor. clean with fine steel wool. You probably thought I was lying when I said that, but I Just found it. Please guys, let's stay focused on our class. Um, damaged wires. Maybe coming out of the back here? Some heat damage on the wires. Something like that like we've talked about. It's a very small current that actually passes through there. The amount of current that you need to see passing through there. You have to actually have a meter that can measure. uh, microamps. So like Milla a million Like point million like a Milliamps micrograms. Yeah, divided by the million. It's micrograms all right. And so it's a crazy small amount of amps. and um, so something like a melted wire. That poor connection. something like that could really throw that off. We don't have a lot of current passing through there. It's got to be clean. If you guys have this HVAC school app you're going to find in the checklist exactly how to test your flame sensor. I Am running a little low on time, so um, uh, I will show you this when we install our new flame sensor today. Um, but we'll walk through these steps. Here's some things to test and this is really important that we talk about this. It senses current through the flame to ground, Right? So if we have a poor ground, if we have a poor neutral terminal coming in, poor connection, or a neutral terminal rust or something on our ground wire connection, we don't have this cleanly grounded to our neutral to the same side that our Transformer is cleanly grounded to, then current is not going to pass through. And so you will pull this error code with the flame sensor when actually it's just a grounding issue on the furnace. so you can check between ground and your neutral leg coming in. So first connection point from Power neutral ground here. Do we actually have a good connection? Okay, my unit's grounded. Well move on to other diagnosis areas. With that is my board actually sending the current. You can test that uh with microamps testing which we'll do that. Um, let's jump straight into uh actually installing a flame sensor. So I have a flame sensor. Uh White Rogers has made a flame sensor. Um, that uh from Emerson and it's a universal premium flame sensor. It can go in so many different applications. they actually have a chart on the box. They have a chart in their app. if you go to the white Rogers app that you can type in the part number of whatever flame sensor you're working on oil, boilers or cooking equipment or furnaces or pool heaters, you have that flame sensor type in that uh uh, the actual part number of that you can see if it's a match here in the match description. They will actually give you like color codes for what needs to be done. No change can be done on green or we need to bend it on the blue. Um, so. but let's go ahead, come on and join. So we have our flame rod and then we have our wire that comes with it. So these connection points will be the typical sizes you'll see. They also have a backup like a smaller spade and then a screw for securing it and then a shield for if you need to modify it. bending it. Whatever you got to do, you can slide. The Shield over that. Anybody here replace the flame sensor. I Don't think any of you have done this. Okay, so let's go ahead and do it. I'm gonna power down and we're just going to walk through this so you can have this on your truck, check out the part number on the old one, and match up to what needs to be done. So right in here we have our flame sensor. I'm going to go ahead and unscrew the screw that's holding it in place. Pull that out. So this is what you'll do when you have to clean it right here and you can see it's a little bit dirty, right? It's not perfect. You can do a continuity test with your meter from end to end and that would let you know that it's not cracked or actually something damaged in there. So let's pull that out. So this is one that's bent and when it goes in and we have our screw in place, you see the angle. We actually need that exact angle with our our new Rod So that we're in the flame, we have to be in the flame, right? Um, so if you look on the flame sensor, you're going to have a part number right on the base of the flame sensor. So let me go ahead and match that part number up. This is a carrier piece of equipment. Lh33ws take five one and you don't have to do this every time. I'm just demonstrating using all of this. Uh, Z51 So it's right here in the blue. We're going to be bending it, which means it's probably going to be perfectly long. We're not going to actually need to cut it. the other color will be bending and cutting all right. So go ahead and lay the instructions out. You're going to take your flame sensor and position it right here on the graph that it shows right on the base of this line right here. and you decide with the screw, just push that down into the line. So this will be our reference point for our old and our new one right? So now we've lined up which Bend it's the 73 degree Bend that we're going to match it up to. So with that laying against the paper on the bend, then we can take our net our next flame sensor down here. This is our Emerson Universal flame sensor. Well, almost had a screw in the wrong side That would have worked out fantastic. So as you can see when you lay it down like that, our Spades are lined up when they're both pushed in like that. so you can just confirm that. But that's why you do this right here. and then we'll need to bend this to our 73. So to bend it, we just protect the sleeve like this. Now if if you are a little bit messy, you can put some gloves on so your fingers don't touch the flame sensing rod. Now only half of the people out there think that this matters and I'm not going to say where I am on this, but Brian thinks that this matters and he's our boss. So we're going to put gloves on just to make sure we're not putting oils on the flame sensing rod, line that up and then bend that over. So let me put the shield on. and so the whole point that I would line this up is so I'd know my reference point on where to bend. so I can grab the pliers right at the point where the Bin's going to be right and now I know I need to bend it straight down like this. So now I'm going to come over to a sharp surface and hold it in place and then bend it down. It's probably not enough, but that'll be more fun. You don't want to go perfect the first try, right, line it back up. We're gonna have to keep going. It was a 73, not a 35 degree. Bend Okay, so the shield is there to help you not damage the flame. Rod if you gouge it, um, you can create issues with it actually being able to read correctly. Where do we go? Third time's the charm. Much better if you actually hang it off and end like this. This is how they have it on their instructions. If I can actually come down a little bit lower and there's our lineup, we're almost perfect. Foreign. Go ahead. go ahead. No shame. So now I know that as I mount this, we're actually going to be positioned into our flame. so I can take and compare with this one. Now on here. you don't actually need to cut it. It barely hangs out longer than the old one and it's not long enough to actually hit the metal. which is why in the instructions for this model, you don't actually have to cut it. But I'm going to show you how easy that is to do. You got this right here, right? So before you squeeze down on like any heavy metal, might be a good idea for that piece that could come flying off that piece. Boom. Not easy. cool Now, um, if need be, if this wire is damaged in any level, then you have a replacement wire that you can connect back down to the board. This wire happens to be in great shape. It is a training opportunity for you guys and for the rest of the world we'll leave that to the field instead of my most smart place possible. Sweet Boom! So now our flame sensing rod is right here. into the flame, you can see I don't know how well you can actually see back there, but it is thinking right where the flame is going to be. okay. So uh, while I got you here sitting around centered around the flame Rod Let's go ahead and show you how you would test the flame sensing rod. So I'm going to put it down here to my micro amps on the meter and this would let me know is my board actually sending the current through the rod? or is it is the rod actually doing its drop job? Do I have something else going on? And so because it's such a small amount of current I can't use the magnetic field that you would use for larger current. Another nerd fact about this is that it's actually as it passes through the Flames to ground, it um, rectifies the flame to DC voltage a DC voltage pulse. That's why they also call it a flame rectifier. So that Ac voltage comes in and it actually pulses DC voltage and the board will read DC voltage and that's how it knows that it's actually turned on. So let me want to turn this on. We've got the breaker 15 amp up here. Boom! Foreign. Okay, so if we come back to our slide, How many voltage? How much voltage? Um or current? I'm sorry how much current DC current does it say on the last picture? one to ten depending on equipment, but you're typically seeing two to six. All right. So right now we have five DC volts. So typically between two and six and I'm literally making the circuit myself. It's a little bit easier with clamps on the end of this when you're testing it. Um, but you know I'm using meter leads. There you go. New brand new flame sensor works. It's doing its job. Sweet. Safety is what I wanted to talk to you guys about. Next are three main possible issues: Gas Leaks When I put this together for the Symposium there's about four leaking joints and of course I didn't test it. We were just in a rush and right, you guys had so much fun roasting me the entire time for that. It was ridiculous. It was because I was wearing safety goggles really threw me off. Somebody smells gas. Take it. Seriously, they're not just a crazy person. You smell gas. Stop. call your manager, ask people to step out of the area. if it's that bad, ask people. Okay, let's just step outside while I try to figure this out right and understanding gas is heavier than air. You walk into a space and you smell real heavy. It's like super thick down here and you're starting to smell the film, the the the um fumes. My guy understanding that too. About gotcha I will sometimes I'll walk and be like and I'll just go down to the floor because if it's a lot stronger there, we're packed in this space. Everything's got to shut off. We got to ventilate. We got to get the gas out of there. I'm not pushing the manual button for the garage door open I'm doing it by hand like all that stuff you got to be thinking about. Next thing that we want to talk about Carbon Monoxide. It is way more common that people die of carbon monoxide from their furnaces, then gas leaks because gas. They put an odor into the gas so you know what's happening. Gas doesn't naturally have a smell, but they add that so you know what's happening. and typically people can save themselves in that situation. Whereas carbon monoxide. You're not going to smell this in your house. it's the silent killer. And if it's if you have a carbon monoxide issue in your house and it's low enough, everybody's just kind of getting sick. Their immune systems are coming down. You're not really sure what's going on. So what are some things that we can do to prevent carbon monoxide in a home? Warn people about carbon monoxide or to, um, catch it when there's a problem. Like, what? As technicians? what are some of the things that we can do there? Heat Pump: Okay, don't smoke in the house. We create your own carbon monoxide in the house. Okay, but that's we're talking about. Furnaces though. Yeah, yes, absolutely. We have carbon monoxide detectors right in there. Every furnace job that you're going to. Maintenance service, whatever. Find out if they have one in the home that's working, you can stock those on your van. That can be an upsell. This is a much better carbon monoxide detector. uh, than what you have you it. It could take a pretty sensitive carbon monoxide detector to actually pick up dangerous levels, right? You don't want to just only have one that will go off in the event when things are dumping and crazy in the house and people are passing out. Uh, you want one that actually goes off when there's just a very small amount of carbon monoxide in your house and it can warn you that you have a problem that over time is going to cause an issue. And so we do have those Smoke detectors. Smoke detectors. Typical I Don't know the numbers between like parts per million? Um, between a typical smoke detector and one that you actually should have right now that they make that capable of reading. Uh, parts per million that are pretty small. but um, we stock them. Yes, that's one thing. Okay, so that's some uh, prevention that we've done there with detectors as technicians. Prevention that we can do is actually inspecting our heat exchangers. So one common reason that carbon monoxide gets inside your house is that the heat exchanger is completely sealed chamber that does not mix with your air. The gas comes in, the air comes in, the flame is burning through there and it all exhausts through that pipe right here. It does not mix with your home air, it only makes the metal surfaces hot and your home home air passes over the metal surfaces. But if this chamber is cracked, which it will eventually over time, there's a lot of heat there with them coming on and off, or it can rust out. They can be cracked or rust out, and that's when you actually have the fumes and the stuff like that blending with the blower air. as it passes over there. you have cracks and so that's how carbon monoxide can actually get into your house. Yeah, you have to pull out everything. That's such a great question. So one of the best ways of picking it up like on 80 furnace and you have an open furnace like this is you turn your system on. We're going to go through the cycle right now since we haven't done that all the