I've been wanting to do a video for quite some time on gas pressure, testing and Matt milton roberts. Everson were nice enough to shoot some quick videos of testing two different types of equipment. Robert is doing a rooftop unit. Matt is doing a split system and they're showing how they test gas pressure and also Matt, shows us a little bit of adjusting of gas pressure.

Whenever we talk about gas, I have to be very clear. This is only for trained professionals. A video is not a full description of all of this, and you have to follow all best safety practices. One really important thing they showed is how critical it is to shut the gas off beforehand, shut it off afterwards and make sure you get those plugs back in.

It can create a very, very dangerous situation if you do not get those plugs back in and well sealed, and you should always use a combustible gas leak detector to check afterwards, as well as soap bubbles and good old common sense. So here we go. Here's Matt to start with okay guys, so here we are trying to test our pressure gas pressure for my furnace here that we're working with and just a couple of tools that I'm using here today, I'm using two of the test. O5.

10. I smart probes, I'm going to use those in conjunction with the measure quick app. I've got a couple pieces of tubing here that we're going to connect to to measure the gas pressure between the manifold and the manometers themselves, something you may need to look for and find are two little hose adapters. This one is a quarter inch by 1/8.

This one might be a little bit bigger. Both of these are 1/8 inch pipe threads. You can find these at Home Depot or Lowe's, or maybe even your supply house, but it's a 1/8 inch thread. Male NPT to a hose adapter, so you've got different sized hose adapters.

This is a little bit hose it a little bit bigger one. This one is a little bit smaller one so depending on which hose you're using you might need to get one size or the other or get just an assortment of a few, but all of the gas valves going to be this 1/8 inch threatening here also some. I have are my service rent and I have an additional just plain old allen. Wrench both of these are 3/16 3/16 to the number first thing you want to do at our furnace here always is to go ahead and turn off our gas line when the gas valve is in the horizontal position.

In this case it is off or perpendicular to the pipe, so it is off here now I'm going to come down here into my furnace and I have a plug here. This is going to be my supply side to remove and there is another one down here at the bottom, which you can't see, which is your manifold side. So I'm going to take those off here while the gas is off and insert my plug and we'll come back and just decide. Ok, so here we go, we've got everything set up here.

I've got my supply side on and I've got my manifold supply. On a note, when you're working with these 8th inch plugs the taper plugs to the to the hose here, these do not need to be super crazy, tight, just take just finger tight and just barely finger tight. You just want to be able to get them in here and get them snug, so they don't leak, but they don't need to be crazy. Tight.

You don't need to put a wrench on those when you seal them up definitely want to get them tight, but as we're measuring here, tightness is not the greatest thing here. All right. Here's my two manometers down here. I've got one for the supply and one for the main, a fold.

I've got them labeled. You don't have to do that. If you've only got one manifold or one manometer, you can just do this one at a time I'm lucky to have both. So I'm going to do both of them at the same time.

Here all right, so here's a picture: the nameplate label. You see this is model number GME, eight, zero, six, zero, three b NB b. This is the goodman of piece of equipment. That label says that it is an 80 % of fission, 60,000 BTUs of input.

You can see. It's got the rated input there, just below it, as well as the rated output and the temperature rise that is recommended of 20 to 50 degrees down here towards the bottom. It gives you, the maximum gas supply pressures in natural gas is 7. You see the minimum supply pressure a little bit hard to see here, but it is 5 and the manifold pressure is 3.5 inches.

Orifice size is a 45. So that's the information where we getting off of the furnace itself. There, alright guys so here we are. I've got this furnace fired now we are on low stage.

It's showing me that we have a manometer pressure of an amp manifold pressure up to 0.34. We should be at 1.9, so this needs to be adjusted all right guys. Now I am up into high fire on my gas furnace. It takes a little bit of time to get there, but you can see that I've got a manifold pressure now of 3.7 93.78.

So I need to adjust this pressure down, so I'm going to go ahead and insert my my courts tool here and I'm going to move this counterclockwise to get this down. To my three points, they'll see how it looks. Three point: four, nine three point: five. We are good to go all right guys.

Now I've got everything set finished up here. I just need to take all my tubing and everything off here. Just some things to remind you about is once you have finished doing all your adjustments go ahead and shut the furnace down and let it cool down naturally make sure that blower stays on for that full time. So we don't stress our heat exchanger.

Once we get all that done, we're going to put everything back together, I've got my two plugs here. I need to adjust or put back in these were for adjusting my pressures, my manifold pressure in high fire. This is my low fire here, my hi-fi over here. I'm going to take off my to test ports again make sure you shut that gas off now that you're getting ready to remove that, and it's always very important to don't forget to put those plugs back in once you are done so I'm pulling out my plugs Here - and the first thing you should always do is put that plug back in alright, so I'm getting this one plug back in here.

I've got one at the bottom to do as well I'll, pull that one off last thing. Just depending on what gas spring you have make sure you look at your installation instructions. Some instructions, have you adjust the high side, gas pressure first and then adjust the low. Some of them have you just do low first and then the high, if you don't do it in the order that they have specified or told you to do, you sometimes will get gas pressures that are funky in the opposite stage, so just make sure you're following The recommendations of the manufacturer - if you have questions you can always call your your rep or the people at the supply house, and they probably can help you out, maybe alright.

So again, this is Matt with scientific comfort services. Talking to you about checking manifold pressure thanks. So much guys, alright, hey guys, so I am out here doing a service on a carrier package unit that wasn't heating. So what I wanted to do, I was here, will show you how to do how to check your gas pressure.

Supply pressure will have a Max and a minimum. This one is 13 inches water, column or 3.24 kPa. That's our max. Our minimum is going to be 4 inches.

Water column will have a manifold pressure. Naplan is going to be on the high fire. This is a two-stage two inches water column: 25 kPa on our low fire. This is your gas valve here, your inducer, your manifold with all yours, burners and obviously the heat exchangers behind that plate there.

So the places you're gon na check your gas pressure on this one you're gon na make sure and you're gon na see a little port here with an Allen screw and then the same thing. On the other side, you'll have the same screw, usually usually on the same side. Just opposite so we'll take that out and that's how we'll check our incoming pressure and then this one behind here will tell us our manifold pressure. So I went ahead and got those plugs taken out.

Those are them. You can use Allen wrenches, but I prefer to use my ratchet service wrench, just as faster works better, so see that one's out the one in the back on this side is Al. Let me grab the tools real quick you'll use to check, so this guy right here is gon na be a manometer. It does a couple of things.

You can check static pressure with it. If you have pitot tubes, this one is really nice. The fill piece SD mn6, because it will also test pressure switches. It's got a little pump on it that will either pressurize or it'll suck down negative to test those pressure switches.

You know we attach to some hoses here and on the end of them, you will have bits like this one, so that bit is gon na screw into that little hole right there I mean the hose will hook up between this and the manometer to tell us Our pressure, when anti-gas off first always make sure you set shut your incoming gas off before you take these plugs out on these. It doesn't need to be super tight. Just finger. Tighten a couple of turns with crescent wrench is fine, but on our manometer here.

What we're gon na do is turn on 3 and 0 now, so what we'll do is we'll zero it out just to make sure make sure we get a correct and accurate reading go ahead and turn the gas pressure back on. You see me reading about 4 to the point. It don't drop down a little bit as well, when the unit does kick on, just takes a little bit of gas. So let's go ahead and kick this unit go on I'll.

Show you what your manifold right! First days, which is the two or three to six, do you remember the nomenclature said that that, in a nutshell, is checking gas pressure? If you have any questions, I just want to quickly show the adjustment points and the test points on a gas valve that you can see now. Obviously, gas valves vary quite a bit just like Robert and Matt were saying, and so these would be. The two test points, but this is the adjustment point and one thing that a lot of new technicians who haven't worked on a lot of gas might get confused by is they may think that this is the adjustment? This is actually just the cap, so this right here is just a cap that covers the adjustment screw, and so, when you take this cap off, then inside of there is the adjustment, and a big thing to know is: is that when you turn it clockwise you're Going to increase the output gas pressure and when you turn it counterclockwise you're, going to decrease the output gas pressure. When you have a two-stage furnace with high fire and low fire, then you're gon na have to separate adjustment points.

Hey thanks for watching. I want to just state once again that safety practices are extremely important when working with gas make sure to get those plugs back in and make sure to follow manufacturer recommendations. This is the kind of thing you're gon na want to do with the manual open. Thanks for watching we'll catch you in the next video.