# RE: Loud and Noisy Furnace - LENNOX 90UGF Please help.



## amilayajr (Aug 14, 2009)

*RE: Loud and Noisy Furnace - LENNOX 90UGF Please help.*

Hi guys, Thanks in advance for all your help. My Furnace Lennox 90UGF series gas furnace started acting up on me. I started hearing loud sound when I turn it on through the thermostat after a couple of minutes. Also I noticed that when I set the thermostat for a certain temperature i.e. 70 F it will go above that temp by 2 degree F i.e 72 degree F. The thermostat was not doing this before we started hearing the loud sound I have a feeling it's coming from the combustion air blower. When I touched the combustion air blower it was kind of hot and the sound lessen I applied pressure on it. Also the diagnostic green LED while the furnace is on was flashing FAST and it indicated from the manual that it's operating fine which I doubt it. Did any one experienced this problem and so any fix for it? I just want to know if there's a quick fix i.e. like lowering the motor speed or any other ideas before I call a technician which I'm trying to avoid since I'm kind of tight budget now. Please check the pictures. I pointed out where the sound seems to be coming from. Any help is greatly appreciated. Thank you.


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## yuri (Nov 29, 2008)

You need a new inducer fan, the flame sensor should be cleaned and the small hose to the condensate trap removed and flushed with hot water and the fitting where it attaches to the rubber boot cleaned also.


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## SKIP4661 (Dec 3, 2008)

Also, look at the blower deck, you have a condensate leak that needs tended to. The furnace looks very similar to a G26 model. If the inducer is squealing you will want to replace it. Same for a wheel rub. Oiling the bearing usually makes it worse.


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## amilayajr (Aug 14, 2009)

SKIP4661 said:


> Also, look at the blower deck, you have a condensate leak that needs tended to. The furnace looks very similar to a G26 model. If the inducer is squealing you will want to replace it. Same for a wheel rub. Oiling the bearing usually makes it worse.



Thanks so much for the reply. Can you guys assist me on how to remove the combustion air blower? which one is the inducer? is it inside the combustion air blower? You mentioned about the condensate leak that needs to be tended? Is it all part of the combustion air blower that I need to replace? I notice there's motor attached to the combustion air blower but I could not remove it by just unscrewing the motor itself. It seems that I need to dissemble the whole thing. If you can give me some instructions on how to do this, I'll appreciate it. I'm quite confident working with my hands but I just don't want to dissemble it without any idea ahead of time. Thanks.

P.S. Any link or website on where I can buy the inducer? I just want to verify also if the inducer is the motor itself or the whole part of the combustion air blower.


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## amilayajr (Aug 14, 2009)

SKIP4661 said:


> Also, look at the blower deck, you have a condensate leak that needs tended to. The furnace looks very similar to a G26 model. If the inducer is squealing you will want to replace it. Same for a wheel rub. Oiling the bearing usually makes it worse.


Thanks so much for the reply. Can you guys assist me on how to remove the combustion air blower? which one is the inducer? is it inside the combustion air blower? You mentioned about the condensate leak that needs to be tended? Is it all part of the combustion air blower that I need to replace? I notice there's motor attached to the combustion air blower but I could not remove it by just unscrewing the motor itself. It seems that I need to dissemble the whole thing. If you can give me some instructions on how to do this, I'll appreciate it. I'm quite confident working with my hands but I just don't want to dissemble it without any idea ahead of time. Thanks.

P.S. Any link or website on where I can buy the inducer? I just want to verify also if the inducer is the motor itself or the whole part of the combustion air blower.


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## yuri (Nov 29, 2008)

Cozyparts.com. You need to buy the complete unit/draft inducer fan. Give them the complete model and serial#. I am a Lennox tech and know that furnace very well. The inducer is not easy to change. If you overtighten the mounting screws you break the collector box and need more expensive parts. If you mess up the gasket it won`t draw a draft properly and you will have pressure switch tripping problems. The flame sensor is very difficult to get out without breaking and the burner it sits in front of should be cleaned with emory paper also or you get poor flame signal problems. An experienced Lennox tech will know how. It's a DIY world so feel free to learn on your own unit but it is not as easy as some think.


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## amilayajr (Aug 14, 2009)

Thanks Yuri. I'd figured that it's hard to remove so I didn't bother dis-assembling at all. Thanks for the info about the parts. By the way, since you're a technician, do you happen to have a manual on how to remove it by any chance? at least some step by step guide? Also by any chance since you're in canada do you have some idea as to how much this thing cost to get replaced by a qualified technician like yourself. Just in case I opt out of just having it service at least I have somewhat idea as to how much it cost so I don't get jacked too much. Thank you for all your help. Looking forward for your post again.


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## yuri (Nov 29, 2008)

Where do you live? which city? Prices vary a lot between dealers depending on the size and quality of them. Mine is expensive. All those items I mentioned should be looked after by a Lennox tech and I am trying to help you have no further problems. That stuff is normal maintenance for all furnaces.


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## amilayajr (Aug 14, 2009)

yuri said:


> Where do you live? which city? Prices vary a lot between dealers depending on the size and quality of them. Mine is expensive. All those items I mentioned should be looked after by a Lennox tech and I am trying to help you have no further problems. That stuff is normal maintenance for all furnaces.


 
Hi Yuri, Thanks for the reply again. I live in Brampton Ontario, near toronto actually. Do you know any one here by any chance who fixes this furnace model.


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## yuri (Nov 29, 2008)

Unfortunately not. I would try a larger older well established Lennox dealer. That furnace requires someone with experience with it to get the flame sensor out etc and do what I said. Nothing against the smaller guys but you would hate to be training a newbie on your unit. The larger Lennox dealers pay better and can retain/attract better techs from my experience and they have Lennox training and tech support. You get what you pay for sometimes. Give them the list of items over the phone and ask them if they have someone who knows about them and can do them. Ask for a senior tech. If they don't sound confident try another one. Check them out with the BBB first.


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## Yoyizit (Jul 11, 2008)

My manuf., Bryant, sent me a Factory Service Manual for free for my '82 furnace.

Trible's sells consumer-oriented "RepairMaster" books for appliances; maybe someone publishes similar books for HVAC stuff.


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