It might be part of the reason why this coil's not working very well, but when i cut the lines it's spewing out oil, so this coil might be logged with oil, so watch out for that kind of stuff. Yeah, it's coming out the bottom too, so nasty nasty. This video is brought to you by sportlin quality integrity and tradition got some coach drawers today that uh we need to diagnose. We had another service tech here and he had to top off the charge.

A couple weeks ago, probably about a month ago, to be honest with you, so uh we're here to try to find the leaks, and then i also noticed that a couple coils are iced up, so we're going to knock that out too. At the same time as our early morning start we're working on changing some drain pans too. This guy right here got our first coil. It's got some ice, but we're doing a quick leak check and the leak detector was kind of going crazy in here see.

If we can duplicate it all right there, we go clearly picking something up, so we're gon na get some soap bubbles on this guy. Okay, we got some big blue right here and uh. We got it right in there and it looks like it's leaking inside the coil, so we're gon na get this little bit of frost, melted right here, we're gon na measure, the coil um and then we'll quote to replace a coil and a txv. Everything else is looking okay, so i don't think we need to go any further than that so coil and txv on this one and we'll mark it coil one and then we'll move on down the line to the other one.

So i was able to get in here: pull the drain, pans, change them and just use a tiny strip of electrical tape to just seal them to that half inch line, but it starts uh sits in the half inch and then the screws for the drain pan. They were coming from the outside in, but i put them from the inside out for the next guy, so this one's good, this one's good, i got ta secure that uh, vinyl or plastic hose into the side of this coil, but yeah much better. Now we got to the second coil we're not finding anything, but we are going to talk to the customer, because the txv looks like crap, or at least the powerhead does, and the coil itself doesn't look the greatest either so we'll give them a big picture quote: Give them the option to change this coil if they want to, and then now we got to get to the ones over here and this one, this one's all iced up, pretty bad, so we're gon na get it defrosted. We didn't find any leaks in that coil.

So we'll get it defrosted, but the coil itself is in really bad shape, so we'll bring it to the customer's attention again. We got pictures of everything too. So this drain isn't clearing. So i've got my tool right here that uh i've shown before, but we're i've got two people here, so we're gon na have to do is take the covers off of every one and then plug them up and blow them out one at a time to clear The drain we're on the roof now we're going to leak check all up here.

So we know the system's equalized out always hit the low or the pressure controls, because those are always a very common place for there to be a leak just kind of check around. In there yep picking it up in the dual pressure control yeah it's hit and miss it's very small. Oh there you go, so you always want to check your dual pressure controls and then we're going to check the rest of the unit under the compressor. I've seen them rot out under there again, you don't just stop at one leak.

You keep going if you can, because more than not there's multiple leaks, so just kind of checking everything even before i put service gauges on it, because we know that the system's equalized out. I also see a little bit of oil over here. I don't think it's a leak, but we'll just check it yeah, it's not picking anything up, just dust and crap moving around it's another one of those old compressors. I just changed one of these.

This is an o4. It's going to kick its bucket here. Pretty soon. Probably these things get massive abuse, i'm not seeing anything else up in here, so we'll leak check the receiver and then the condenser real, quick, condenser right here, typically don't see leaks on this side.

You'll see them on the other side if they are there, but i'm not picking anything up so we'll check the other side now, and it's not looking like anything in here, you think you'd see oil or something uh receiver is in decent shape. Don't see anything major with that, you always want to look at the valves. The valves typically get messed up, but i'm not seeing anything so we're looking pretty good all right. I'm gon na put this guy back together and start it up and then check the liquid level on the receiver.

All right. We're currently pumping the system down. I'm gon na go ahead and pull my prop out. So what we did was we closed.

We front seated. The valve on the receiver, and that stops the flow of refrigerant coming out of the receiver, but the compressor continues to pump until the low pressure control cuts it out. So the flow stops out of the receiver coming out of the receiver goes through the dryer to the expansion valve and or expansion valves - plural, but because there's no flow coming out of it. The system is basically running out of refrigerant in air quotes, but it still has refrigerant, but it's just stopped so now it's sitting there at 4 psi.

If we needed to do evaporative, coil repairs or any repairs on the low side. We could do them now because it stopped at that valve. But what we're doing here is we're going to check the liquid level in the receiver, so we're going to take a heat, producing device, warm up the receiver and find the spot where the temperature changes on the receiver and that's going to be the current liquid level. When we run our fingers up here, sometimes i'll do a thermal camera too, but not this time.

But when we run our fingers up here, the temperature change happens right here. So our liquid level's right here - and we last left it up here so obviously we're low. So we're going to add some refrigerant until the liquid level gets up to where the three-quarter mark is we're, checking the charge and this unit has or this system has a head pressure control valve. In fact, every one of these have head pressure control valves.

Therefore, they take extra refrigerant because the head pressure control valve floods, the condenser in low ambient conditions to try to maintain a pressure differential, keep the head pressure out easiest way. Okay, in order to flood the condenser, you need extra refrigerant in the system, okay, more so than just a clear sight. Glass. If this system did not have a head pressure control valve, we could add refrigerant until the side glass is clear once the box gets close to being down to temperature and it would be charged appropriately assuming everything else is working correctly: okay, but because we have a Head pressure control valve, we have to add that extra flooded charge.

So you can talk to the manufacturer. The manufacturer of this box actually publishes the data and tells you how much refrigerant this system takes with the flooded charge in consideration. Okay, but here's the problem, we're topping off the charge on this system. The sight glass was not flashing.

When i got here, i just know that it has a leak, so it's only leaked out some of the flooded charge, but it's not showing any signs of a refrigerant leak. I marked the liquid level the last time that we worked on the system. So, therefore, i was able to pump it down and check the liquid level and see that we were below the level that it was last time. Therefore, that's the amount of refrigerant it's low if we calculate the charge using spoiling 90-30-1.

That would be the second best way besides talking to the manufacturer, but that's not practical, because spoiling's method, wouldn't we wouldn't know how much refrigerant has leaked out at this point right now, because we're not flashing, okay, we're not showing any signs of being short at the Moment so the only way that i've come up to be able to do this is to mark the liquid level after i'm done with the repair okay, so we mark it at the three-quarter mark now adding to the three-quarter mark or filling it up to 80 percent. That's the maximum amount of refrigerant you can safely put in the system. Theoretically is too much gas. The system will operate, but it's technically gas that the system doesn't need, because that extra refrigerant potentially will never be used.

Okay, past the point of the calculated charge and, for example, i will give you this. This is their beer walk-in. I did a repair on this and i marked the liquid level at the three-quarter mark and i wrote on there 36 pounds of gas okay. So to get it up to the three-quarter mark, i added 36 pounds of gas, but using sporland's method, 90-30-1 or leaning on the manufacturer.

If we come over here, the system only needs 25 pounds of gas okay. So you understand, in order to fill it up to the three-quarter level, we added an extra 11 pounds of gas. Technically doesn't need it, but it's the only way in the field that we can do it now. If we were to do a repair recover all the charge and weigh in the factory recommended charge, then we could mark the liquid level and know from that point forward that that's the right amount, but in the field you don't always get the option to do that, Because you're making a quick repair, you're topping off the charge and the only other way is to fill it up to the three-quarter mark, which is the absolute maximum amount of refrigerant you can safely put in the system when it's pumped down, okay, hopefully that makes sense.

I get a lot of people saying you know, don't do that, but unfortunately there's no other way to do it without recovering the charge right. So it's super early in the morning we're gon na change out all these coils. So what i do is take all the drawers out so that way they start calling and then i'm going to go upstairs and we're going to pump the system down so we're just pumping it down change all the evaporative, coils and txv's still dark outside 99 of The time i'm the first person to get to these jobs, i usually schedule everybody like this time. I scheduled everybody at six a.m and uh.

I have two other guys coming and i usually get here around five. Five. Thirty just gives me time to get everything ready and stuff, so we're gon na open this guy up and get a pump down now. Originally, i was gon na change, a suction line service valve on this guy too.

In all honesty, i forgot about the suction line service valve, so we may or may not change it this one right here, i might have one in my van. I might not so we're gon na have to see, but we're just watching this guy pump down the suction pressure is gon na continue to drop, and once it gets down to zero or close to zero, we'll turn the system off. Take the low side hose off. So the system can have a pressure relief while we're brazing downstairs, so you can see that the refrigerant the flow is stopping and we're slowly.

Pumping down you see, the low side is dropping dropping dropping. I have a screwdriver right here to bypass the pressure control, the low pressure control, so that way i can pump it down to about four or five psi without it. Shutting off. Oh, it looks like we might be overcharged on this guys because you see how high this head pressure's coming.

Someone else has been here adding gas to this, and i have a feeling we put too much in it. We'll have to deal with that in a little while all right, so we're running we're running we're running - and i say right about here - is where i'm going to stop it. I pulled the pressure control out and then what we're going to do is just take this low side hose and just let it bleed to atmosphere that is a de minimis loss, we're just gon na. Let that bleed the atmosphere and then uh we'll go downstairs and start doing what we're doing and uh, because this guy looks you shouldn't be coming up to 400 psi when it's pumping down.

So i might send a technician up here, one of my guys to recover the charge that way we can just uh make sure that we don't overcharge it when we're all done. Okay, we got four coils. Four txvs got those guys right there, so going to town trying to get them out. The first step is get them ripped out and then we'll figure out the piping, because on some of these this one right here, the txv i have is different.

So we're gon na hope we can make it work, so i got my coil mounted in there and then the top suction line coming out of the coil fit right back onto the coil, but i did have to cut the liquid line right at that t. So i'm just going to make a piece real, quick with the bender going right down to the txb, we're going to sweat that one in and then jump onto the next one. Next one's gon na be a little more difficult, but we'll get it figured out. Got too much going on to actually show all my work today because we're trying to knock this thing out, but i just bent a couple pieces going up and in it's all sweat in we're gon na mount the sensing bulb and then move on to the next One and then we got two more going down there.

It might be part of the reason why this coil is not working very well, but when i cut the lines it's spewing out oil, so this coil might be logged with oil watch out for that kind of stuff. Yeah, it's coming out the bottom too, so nasty nasty all right. We got this coil in. We got that coil in over there that one was a little funky on the top good, whatever it's all good, it's just the uh.

The copper line up top was like bent kind of funny, but it's all good, we'll straighten it out and then that one over there is already done so we're assembling these. We got to turn on the fan motors, make sure nothing's hitting and then we got to go upstairs change the dryer and vacuum everything down. Sometimes i get lucky um. I've got uh rotolock valves here, so i usually keep an assortment of them because we go through them.

I think that's the one that i need. That's a oh! That's a 5 8. Now i think i need a half inch. Are they? Oh? They might be all 5 8.

well. I can always bush it down. If i need to um yeah, i think it is that one so i'll just take a bushing if i have to so. I actually lucked out, because this is 5 8 and that's 5.

8., that one's a flare so we're going to eliminate the flare brought a piece of 5 8 pipe. We can just unsweat it from here, make a new piece all the way down into the fitting. I had to get my big boy wrenches because we got to get those guys off now. Yeah this service valve is not happening.

Okay, so here's my logic here. I've tried a bunch of different wrenches and i can go get a breaker bar. But if you look down in here, it's starting to stress the rotor lock fitting coming out of the compressor it's gon na it's gon na crack. Something is what it's gon na do.

So this compressor is a 2004. I'm telling you it's going to be replaced here. Soon, it's going to go out so we'll change that valve when it goes out, but you got to know when to call it. I've already tried heating it up.

I got my torch right here. I tried heating it up, it didn't break free and again you have to be careful because i can keep going and getting a cherry hot. But what happens if i melt the gasket inside and i still can't get it off. You know you have to know when to call it and say: hey enough.

Is enough, so we're not going to try to change that valve anymore, we're just going to jump onto the dryer, we'll change that valve when we change a compressor. All right got my spoiling catch all and see all dryer and sight glass installed. As usual, i go with the flare, dryer male female sight, glass. So i haven't pulled the evacuation.

That's why it shows moisture in there right now, so we're gon na get all the vacuum crap hooked up, get it sucking down and uh, hopefully be on our way soon, when you're doing the evacuation as much as possible, you want to put all the caps on So i put the cap on the suction service valve and the liquid line king valve back there. It's currently at about 1500 microns back there, it's a little hard to see 15 23 1507, so we're just going to let it run and we're just kind of cleaning up on the roof. I'll start, putting some tools away and stuff trying to be as efficient as possible, still pulling down um i this is. This is kind of monumental.

I swear that nylog lasts forever. I rarely ever use it because all i use it on is flare nuts. I finally just went through a thing of nylon, and i kid you not. I've had this for at least a year um, because you only use a drop.

You know and honestly, if i really wanted to stretch it there's still a little bit down in there. It's just harder to get it out as well. If i stored it upside down, i'd probably get some more use out of it, but i don't want to do that so got a new container and uh. This is, and this shows you how old i have not used a nylon with the new blue style top, and i know that's been around for a long time, because i've been going through old, school bottles of it.

So all right! Well, this guy's still running we're at about a thousand microns right. Now, one thousand one or something so uh. We are going to try to reuse the existing refrigerant. We ended up.

So when i first started this morning, i pumped the system down, but because uh it was going really high on head pressure. When i was pumping it down, i assumed that i had a service tech here recently topping off the charge and he over slightly overcharged. The system, so i went ahead and recovered all the gas out. This will make the evacuation go smoother because we can pull from both sides and we'll go ahead and make sure that we put the right amount back in there and we'll mark the liquid line receiver with a big paint marker that way, everybody knows not to overfill.

It so i went ahead and pulled the vacuum. I front seated the king valve on the receiver and i dumped as much gas as the system would take. It took about five pounds, and now i'm gon na have to turn it on and start adding gas as we're going all right. We are running so we're just adding refrigerant slowly on the low side.

That thing is, is really under a load right now, because uh, those txv's are probably all wide open. The box is like 75 80 degrees, so sight glass is going crazy, so we're just adding gas we're gon na uh, clear the sight glass. Then we're gon na fill the receiver up to the three-quarter level, so we're adding gas slowly. But this guy's really starting to struggle you can tell it's got a lot of liquid refrigerant.

Coming back to it. The compressor itself has kind of got a the whole body's sweating. It's got a really strong vibration to it, so we're just letting the system kind of stabilize out before i add any more gas just being cautious. Put all the drawers on letting them bring it down to temp.

What's happening is because it's hot in that box, every txb is wide open and it's just coming back. You know, so we got to give it some time. So my sight glass just cleared, but i want to make sure that this thing has a head pressure. Control valve because i've seen some of them where people have bypassed them and we just want to be 100 sure before we add a bunch of extra gas yeah, okay cool.

We still have a head pressure control valve right here, so we do need to make sure that we charge it accordingly. So we'll put that cover back on and we'll keep going and we'll uh. So again you can do the the sporland 90-30-1 method. You could measure the condenser calculate the internal velocity or internal uh volume of the condenser figure out how much you want to fill it up for your ambience and then go from there.

We're just going to take the easiest route. We're going to fill the receiver up to the three-quarter mark and pump it down and check the liquid level. So when my sight, glass cleared my liquid level is about halfway, you can see it right there, so we still need to add a little bit more gas. We want to get that up to the three-quarter mark, another inch or two that way.

We know we have the maximum amount of refrigerant in it that we can safely put into the system. Now i've shown this before, but i'm going to cheat because i'm going to go ahead and push the pressure, control and manually turn it on and then just add refrigerant into the low side very carefully and the system still pump down. Then we don't have to wait for it to pump down, but you want to be cautious doing that you don't want to flood out the compressor. You don't want to overheat.

The compressor so see we're still hooked up right there and we're just adding refrigerant all right. We can clearly see where my liquid level is now. So that's right about the three-quarter mark. We've got some marks right there, i'm pretty happy with that, so we're gon na leave it be and we're gon na go and turn the system on and let it run full blast.

So this was actually started probably two months ago, maybe three months ago, and then the repair was done like a month later um and the big picture quote was accepted this time. Okay, so even though only two of the evaporative coils were leaking, i talked to the customer and i said: hey: this equipment is in horrible shape. You know the other two evaporator coils are just as bad, but they're just not leaking. Yet i showed the expansion valves.

You know - and i said you know best scenario here - we replace all four coils we'd be done with it. We knock it out. Sometimes they accept it. Sometimes they don't this time they were like yeah.

Let's just go ahead and do that eliminate the problem. Okay, so we went ahead and replaced all four evaporator coils as you're doing the repairs. You really got to take your time and pay attention to. What's going on, you saw that that coil had a bunch of oil when i was cutting it out.

This particular system there's not really a solution for that. In this scenario, that is economical, okay, of course. The reason why we have trapped oil in an evaporative coil is usually because of poor piping practices. Okay and in this situation, that is the case: okay um, these uh, reaching cooler cooks, drawers different stuff like that oftentimes.

Because of this the size of the boxes and the units. They can't always follow every proper, proper piping practice and especially when you go to individual coils like this um, you know it's hard to get the proper velocity through the system and it just becomes a problem and you have oil logged coils, that's something that is just Part of the game when it comes to these small multiplexed reach and coolers, it just happens. Okay, of course, there's things you could do, but the customer doesn't want to pay that much money. Okay.

So whenever you start to have evaporative coils that are not efficient, you know. What's the sign of an oil logged coil well, in a system like this um, you would do temperature checks across the evaporative coils. We have four evaporated coils. We would go in there and check the temps, see what the temperature differential from return to supply is across the box.

It's almost impossible to measure evaporator superheat each coil. It just doesn't happen because you can't get in there the panels. You can't get probes back there. You know so you just kind of got to work off of your temperature differential.

You can, of course, look at the the evaporative coils when they're operating with thermal imaging cameras, but that's not going to tell you a lot because you know you'd have to take the cover off and it would bypass the air and stuff. So you just start paying attention to tds. So that's a you know whenever we have issues with these boxes. The first thing i do, if we're having temperature issues of course check the charge all that good stuff.

Okay, once you know you have the right amount of refrigerant charge, then you go into each individual coil and you do a temperature check, return to supply and you compare them all. Four coils should be relatively close, but something you need to understand. A td there's no like set td on a refrigerator evaporator, and i mean temperature differential, not um, evaporator td, which is suction saturation versus return, air temperature. Okay, it's not that one! I i should say delta t is probably what i should say: okay, so you check the delta t across the evaporator coil, and you know typically on something like this you're going to see five to eight degrees.

Okay, it's rare that you're ever going to see 10 degrees. It's going to be 5 to 8 degrees, delta t, and you start paying attention to that. You you look and see where the discrepancies are. You can sometimes assume it's an expansion valve.

That's usually going to be your first step is, if you're not getting a good delta t across the coil you're going to go ahead and replace that expansion valve, keep in mind it's. If it has a strainer on it, you can pump the system down, but on these smaller coils they typically don't have strainers. And if there is a strainer it's in the valve, which is just kind of silly, you know and they're not accessible, because most of the time they don't use the the valves with the removable strainers. So just start working your way through that you see oil related issues, you know always be prepared for that kind of stuff.

So if you're ever trying to unsweat a txv on one of these coils like just trying to change the txv um, i always recommend pulling the power head pulling the bottom of the valve. Apart just gut the valve inside the box before you unsweat it because you can get a flame out, you can get a surprise when you're unsweating and all of a sudden all that oil ignites and then you get a little flame so always try to unbolt the Valve take it apart before you try to unsweat anything and cut out as much as you can. Okay, so we ran into an oil log problem, we're always paying attention to that um. Once we got through that, we worked our way up onto the roof um and started the evacuation and again paying attention when i was uh or pumping the system down at the beginning of the job.

Well, when i went back to change the coils, i noticed that the system was looking like it was overcharged. Now what happened with that was in between this job, because it was a couple months before the customer approved it in between the system went low on charge. Again, they had issues and we had to go out and top off the charge. At that time i had the service technician that went on site, go ahead and change that dual pressure control.

I had him change the dual pressure control, because that was an easy repair. We knocked that out. So that's why you didn't see the replacement of the dual pressure control in the video when he did that he overcharged the system. Okay, he made some mistakes.

It is what it is. It all worked out. Okay, we had a discussion about it, but when i was pumping it down, you should never see the head pressure go up to 400 psi, that's a clear sign of an overcharge. Now it didn't shut off on high pressure and i did not get it on film, but while i was downstairs changing the evaporator coils, i had another service technician because i had three people on site, including myself.

I had another service technician, go up onto the roof and go ahead and recover that refrigerant and then, when i went to go charge the system, i still had a lot of refrigerant left in that cylinder. So clearly it was overcharged, even when i filled it up to the three-quarter mark. At the very end, there was still refrigerant left in that recovery cylinder. So we were clearly overcharged now that i said that two times um so after that uh the system came down to temperature uh.

Since i did this job, it has been. It has been a month now. I think uh because i'm looking at the date stamps for this video and it was sometime in november right at the beginning of november, when i actually completed the work on this, so um everything's been operating fine, but it's all about taking your time right. Everybody makes mistakes we do, but you know the discussion i had with my technician: the overcharge situation, like that's dangerous, you know he's putting himself at risk over charging a situ, a system like that, and we don't want to do that.

And yes, i understand people get tired. I don't remember the circumstances. It could have been the middle of the night who knows but just something to remember. Whenever i'm on a job i'm committed to that job, i shut everything else down.

Okay, i got stuff going on at home. I got craziness, i shut it down, i'm there on that job. The way that i look at things is, if i go to work, i'm leaving my baggage at home. Of course, i still think about it, but i'm leaving my baggage at home.

I am focused on work now. If i can't leave my baggage at home, then i stay home, okay bottom line. If i'm not going to be able to fully focus on work and do my job right, then i'm not going to go to work and that's how i view things. I think that's the most important thing we can do is when you go to work.

You go to work. Okay, don't do a job half-ass right, we're there to do it to the best of our abilities within the customer's scope and what they want to pay for right, we're there to do it within our abilities. So um we had a discussion about the overcharge okay and it happens. You know it is everything's fine, it all worked out.

We made sure we rectified the situation, but it's always important to check the charge right um. I think that's it on this one. I really really appreciate you guys making it to the end of this video. Of course, you know um.

I sometimes especially lately. I've been getting a little worn out and burnout kind of with the youtube thing and i'm trying to find my happy place within it. I'm trying to find what's gon na work for me, because i'm reaching this point where it's starting to get a little bit like you know three straight years of minimum two videos a week, three straight actually yeah three straight years of live streams every monday, starting to Get to me so i'm trying to find the way that i want to do things, maybe changing something up whatever, because i love making these videos it's just the process of sitting down to edit them, and i have some mental issues. I know i do and when it comes to like knowing that i have to do something like i have a hard time, uh planning things out if that makes sense, i'm just kind of weird so uh apologies if uh quality and stuff like that, isn't really the Way that it has been in the past, i'm still just kind of working through some things trying to find my happy place and uh.

You know, hopefully we'll get things back up to where i feel they should be soon, i'm working on it also. I have something really cool that think i think is going to make me. I think this kind of happens every year, but i've got something really cool coming up. I think that's going to make me feel a lot better about things.

So stay tuned there'll be a really special video, releasing uh here in the next couple weeks, um where uh i'm gon na, do something cool so stay tuned. For that i really really appreciate you guys. Remember. I try to do live streams monday evening.

5 p.m. Pacific! On youtube also go live on the hvac overtime, youtube channel friday evenings about 6 05 p.m, pacific, with my buddies, there's links in the show notes to all of that. If you guys haven't already, please check out my website help to support the channel hvacr hvacrvideos.com merchandise, available on there ways to support the channel uh. The easiest way is simply watch the videos from beginning to end um without skipping through anything.

If you want to purchase any tools, go to truetechtools.com use my offer code, big picture. One word. As of today, uh december 4th of 21, you get an eight percent discount on checkout and uh yeah uh patreon, youtube channel memberships, paypal, there's links in the show notes to all of those. If you want to help support the channel that way and yeah that's it, i will catch you guys on the next one: okay,.

.