Changing a gas furnace blower motor

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Changing a gas furnace blower motor

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About This Video

In this video we take you along to replace a blower motor in a gas furnace.

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Video Transcript

Full spoken dialog from this video

All right guys, just walked in here and diagnosed this bad evaporator blower motor on this gas furnace. Thought I'd kind of show you how we diagnose that as well as go through the repair process along with you. I already took my nice clean work shirt off, I'm ready to get down to work now and get dirty and do some business, walk you through the process. Ooh, it is hot up here. Let me show you guys some things that are unfortunately typical in our area that really just make for a system that doesn't work as well as it should. I'm going to have to stop the camera and turn it around. So right here on our return, they've got it blocked off here and over there because whenever they replaced this furnace, they didn't want to replace the plenum because that looked like too much work to them I guess. So what happens is you've got this much air here blocked off and you've got it on the back side there too. That really puts a strain on this system. Probably didn't help this motor last any longer. It's really just kind of a poor install. It's not uncommon to find systems that look like this in our area. You can see the flue pipe is barely hanging on so we're going to make some other recommendations I'm sure before we get out of here. But for now, we're going to get this man some cooling. I'll show you how we diagnosed this one. I went up here and the first thing I saw was that I could jump out the wires right here. I didn't have to go to the board and jump anything. So I just kind of let these hang out like that and press this on. Must not be making contact. You can hear the motor, but there's no action. Grab our handy dandy meter here. And we can check our capacitor, which is a 15 microfarad capacitor. You can see that we're reading exactly 15. So this is good. So we heard the motor. We know the cap's good. It really only needs one thing, which is the motor itself. If I was still not certain, I could also do this. I could find one of these wires here, I think this one, we'll turn that on, and take an amp draw on the motor when it's trying to run. See that, 28 amps. That's way too high. That motor's completely locked up. And if I reach in there and spin it, I can actually feel that it's locked up. So now we've got to get this motor out of here. On this one here, what it looks like I'm going to have to do is, first of all, find the power switch, which looks like it's, I don't know where it's at, way over there, I guess. I'm going to do my straddle move, it's dead. And it looks like what I'm going to have to do here is slide the motor out and then take off this thing that holds the board. Let's see what I'm doing. And there's one down there that I probably can't get with my drill, so I'll grab this nut driver. You can really see how dirty and dusty this thing is. It hasn't been taken good care of or maintained very well. I'll try to set you right there, guys. And let's see what happens if I start pulling on this. I've got two more I've got to get. The top and the bottom. I'm going to bring this back once I get it pulled out. Alright, so my phone's overheated here so I can't use the flashlight on it right now. But basically I've slid this motor out, now I've got to get these off so that I can get this board and everything out of the way so we can yank this whole blower assembly out and go outside on the tailgate and work where it is probably 30-40 degrees cooler than it is in this attic. So I'm going to get this off guys, I'm really hot, and then I'll be back. Alright, so we got the old blower motor pulled out and you can really see just how nasty and gunked up this thing was. So we're going to go ahead and take this motor out, clean this wheel up, install our new motor, go back and install the whole assembly back into the furnace itself, tidy up a couple little small things we saw in there that need to be done. There's actually some holes in the back side of the furnace so when that blower motor's kicking on, it's actually sucking in that hot attic air. So we do that, we'll go over there to that guy right there, and we'll check the refrigerant charge and probably give it a quick little hose rinse, and hopefully this gentleman's going to have some cold air again. It is a holiday weekend, it's Labor Day, the weekend of Labor Day, so no one's open today so I don't know what happened to my camera, I don't know where it cut off, but it's a holiday weekend and I'm not even 100% sure that this is a three-quarter horse motor. It's a five-ton unit so I'm hoping it is. If it is or if it isn't, I'm still going to put that motor in it for now so this gentleman can have cooling through the weekend, and if I need to come back and put a different size in it then I will, but most five-tons are three-quarter horse. Sometimes you get one that's a full horse, but that's not super common, but it's not unheard of either. So we're going to go ahead and get this sucker put back in. I don't know how much footage I'll get of the actual pulling out and putting back in, but I'm going to try to get as much as I can for you here. We're going to go ahead and try to get all this crap off of here, off this wheel. I don't know how much we'll actually be able to get off with this water. Eh, looks like quite a bit came off. Nasty, nasty. Nasty, nasty. This is why it's important to take care of maintenance and stay on top of it, because you don't want to, if there's any homeowners watching this, you don't want your motor to look like, or your wheel to look like this one, because that's nasty. You're breathing that crap. It's making the motor heavy, making it work harder, and it's preventable. It doesn't have to get to that point. Okay, I'm going to set this phone down and focus on this for a minute, guys. I'll show you where I'm going. Alright, so I cleaned it off the best I could with the hose. This one's so far gone, it would need a lot more than a hose to get it spotless. But it came really clean, all things considered. I don't know if you can see it, it's much, much better. There may be a shadow on it, but it looks a hundred times better than it did. Much, much better. I'm going to let that sit out here and dry in the sun while I get this motor bracket here to put on the new motor. Okay, guys. So, one of the things you should always do, anytime you pull a motor out, you've got this good access here to the heat exchanger, is inspect that heat exchanger, because this is about as good a look as you can get at one without yanking the whole thing apart. So, I've already looked at this one pretty good earlier, but I forgot to mention it and film it. I didn't see anything that looked awful concerning. And, the other thing I'll mention is, even though this capacitor here is a 15 and it's brand new, just so happens that my new motor requires a 15 microfarad capacitor to operate as well, I'm still not going to use it. Never put a new motor or compressor in a capacitor. It's just asking for a callback or a problem that's just not necessary. Give the customer what they paid for. So, we'll discard that one. And, I've got a nice pretty one here. I'll probably wipe this down, but it's getting really hot. I need to hurry. Yeah, I'm going to slide this sucker in and show you in a minute. My flash won't work on my phone right now. Alright, got the motor in here. Wipe this down. I know it doesn't look like it, but I did. It's like stained. I like to use zip ties, but I'm all out. So, I had to use electrical tape right here. And, I know some people disagree, but I actually like to use these factory installed terminal connectors right there instead of making my own. And, I like to wire nut these. I just feel like it's a more secure connection and less likely for an issue. New capacitor, new motor. Cleaned up. Nice and secure in here. Let's turn it on and see what happens. He just turned it on, so hopefully there's no delay. Is it blinking on the thermostat? I'm sorry? Is it blinking on that thermostat? No, it's not. It's not? Can you turn just the fan switch on? Yeah. It's motor cold for about 11. It says the manufacturer said for about 11 amps. I've got the door off right now. It says it's about 11 amps. I can get whatever that's doing right there. I don't know why that ain't doing that up there. Alright. Customer's cooling. System's running good. I'm going to put a little screenshot from the field piece probes of what my refrigerant pressures and temperatures looked like. Had about 11 degrees of super heat and 15, 16 degrees of sub cooling. There's a piston metering device. It's pretty hot in the house, so my suction pressure was kind of high. It was like 81 PSI on R22. So that kind of drove it up a bit. It was a little hot outside as well. It's 91 right now. Hot in the attic, though. I know that. So there's a lot of heat getting into the evaporator just through the metal casing of the furnace until that thing cools off. Those pressures are going to stay high. Yeah, so that's what we do when we change a blower motor. Change it out, clean it up. Gave the gentleman options for a replacement furnace. He didn't want to do it right now. No problem. He's up and going. There are definitely some more things over there that need attention, and he's aware of those things. But for now, he wanted the motor, so that's what we did for him. What else? Oh, went in to check the heat exchanger while we were there. Couldn't get good footage of that because I didn't have good lighting. But the heat exchanger's fine. Other than just kind of being installed without a lot of pride, relatively poor craftsmanship in the installation. It runs okay, I guess. It's definitely not the quality that our company would install a unit to, but you know, it's working, and he doesn't have to replace it today, so he's happy. Going now to another call where it sounds like they're going to be low on refrigerant. We added R22 to their unit last year. Here we are in August, or no, September. Here we are in September, and they just need to squeeze by a little bit longer until they can do something more permanent like replace the equipment. They don't want to replace it right now because the big freeze we had back in February caused a lot of damage to their home, and so they're recovering from some expenses that they incurred from pipes bursting and flooding their house out. So we're going to go over there. We're going to see if we can get the refrigerant topped off. We may get some footage over there. I may not. I don't really know quite yet. It's about 2.30, so I kind of want to start wrapping my day up and get home to my family, but I did want to make a video. I hadn't made one in a while. I'm going to try. I know I always say I'm going to try to make more videos. I make about one a year, so I'm really consistent, if nothing else, but thank you guys for watching. If you need anything at all, you have a question, happy to help, reach out. Love helping other technicians. Love helping homeowners. Anybody who has a question, please reach out. We're here to help. Thanks.

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