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Questions tagged [lennox]

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Replacing blower on furnace and it’s filled with water

My blower was failing on my old furnace and I am replacing it. It sounded like there was water sloshing around inside it but I assumed it was just the bearings wearing out and that I didn’t know what ...
Charles's user avatar
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0 answers
143 views

Lennox 96% Furnace Pressure Switch Fault and Schematic Diagram

Furnace: Lennox EL296UH090XV48C - 06 Installed: August 2015 We see E227, E229 and E271 for sometime. Overall, the codes mean that low pressure switch failed to close (hence inducer stopped and furnace ...
blackroses's user avatar
1 vote
0 answers
82 views

How do I connect a C wire or C adapter to an older Lennox furnace with no terminal strip?

I have an older Lennox Conservator 3 G16 with no terminal strip. How do I connect a C wire or C adapter? From what I have seen online nothing matches my furnace.
Reylene 's user avatar
1 vote
1 answer
2k views

Lennox Wiring for Ecobee SmartThermostat

Confused by the wiring, hope someone can help me out. At the furnace there's only four wires in the cable (R, B, G, and W), but at the other end, a yellow wire appears. It's not reflected in the ...
Sassbearilla's user avatar
1 vote
0 answers
49 views

Lennox G40UH erratic behaviour

I've spent the last couple of days troubleshooting my Lennox G40UH furnace. A couple of weeks ago, I noticed that the furnace would sometimes come on briefly (anywhere from one second to a couple of ...
Michael Cooper's user avatar
2 votes
1 answer
1k views

Connecting C-wire to Nest Thermostat for Lennox HVAC

My Nest thermostat has been running fine for quite a while, but recently it started complaining about low battery and wi-fi gets shut down due to power issues. I've been looking for the answer, and I ...
scifi88's user avatar
  • 21
0 votes
2 answers
357 views

Lennox gas furnace maintenance

I bought brand new Lennox HE natural gas furnace 3 years back. It has been running perfectly. My dealer recommends to do a preventive maintenance because of 3 years time span. I regularly change the ...
gmail user's user avatar
2 votes
1 answer
745 views

How can I be sure to get the correct replacement limit switch for my furnace?

My furnace fan was running constantly and the heat would not start. Through some research I discovered this was likely due to a faulty limit switch in my furnace. I don't have the exact model of my ...
Trashman's user avatar
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1 vote
1 answer
1k views

Vibrating PVC exhaust pipe from high efficiency furnace

We have a two year old house that has this heating season developed a vibration in the exhaust pipe that can be heard on the first floor of the house. It seems to have decreased as the season has ...
John Kiczek's user avatar
0 votes
3 answers
3k views

Updating old Lennox thermostat - wiring confusion

I am trying to update my old Lennox thermostat to a Sensi smart thermostat. I checked the compatibility on the Sensi website and it appears to be a match except for this cluster of wires on the left ...
Jtoxx's user avatar
  • 1
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0 answers
134 views

Lennox G40UH furnace not turning on

With the lower panel door switch closed, the combustion air inducer comes on. It runs for a little while and then shuts down. Nothing happens in the meantime. The system was working fine until this ...
Mahendra26's user avatar
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0 answers
353 views

Lennox G12D2E-55C-6 with a Johnson Control G779LHA-1 ignition control and Mercury Thermostat

I am looking to replace the mercury thermostat with a Lux Kono thermostat simply to have the ability to run the fan only and circulate the air. I believe this thermostat does that periodically. I'm in ...
Richard Thompson's user avatar
2 votes
1 answer
9k views

Why is my air conditioner running when the house is below the set temperature?

We recently had a whole new system installed for HVAC. We had a lennox furnace with dehumidifier and UV thing, along with the exterior lennox condenser for A/C. We have the iComfort S30 thermostat, ...
Barry Chapman's user avatar
1 vote
2 answers
530 views

Lennox G23Q3/4-100-2 And Ecobee4 [closed]

**Pictures attached to go along with my rambling explanation I have my Lennox G23Q3/4-100-2 natural gas furnace and my central air system that has been working since 1995 on a basic programmable ...
John Weidauer's user avatar
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0 answers
226 views

Is it safe to replace a Furnace pressure switch with one of a different rating? [duplicate]

So I had some problem with my gas furnace and a technician came by to install a new one but it doesn't have the same rating and only has one tube instead of two. He assures me it's fine but I thought ...
wjcmogui's user avatar
3 votes
3 answers
20k views

Is it safe to replace a Furnace pressure switch with a different one?

So I had some problem with my gas furnace and a technician came by to install a new one but it doesn't have the same rating and only has one tube instead of two. He assures me it's fine but I thought ...
wjcmogui's user avatar
0 votes
1 answer
3k views

Not able to find Lennox ML193UH furnace filter

I have a Lennox Merit series gas furnace ML193UH in my attic. The furnace turns on, but no air blows out of it. So i figured the filter needs to be changed. But I'm not able to find it. The pictures ...
Jaimin's user avatar
  • 1
-1 votes
1 answer
234 views

Ecobee3 lite connected to Lennox Pulse G14Q Heat/Air Condition

I have read a similar wifi thermo connection feed here and they had success hooking the C wire to the T terminal on the furnace. I can get power to run the thermo from the T terminal, but when I do, ...
GearheadKen's user avatar
2 votes
3 answers
12k views

How do I connect the spare C wire to the old Lennox system (model # lennox g12q4-110)?

I am trying to install my Ecobee3 now. After finishing the connections, Ecobee did not power up. I did some reading and I believe the C-wire, though it is available is not connected to the power at ...
Visu's user avatar
  • 21
0 votes
1 answer
52 views

Lennox HE propane furnace

I have a Lennox HE propane furnace in the cottage that is set to 41 degrees when we are not there. We head up most weekends and when we get their I boost the temp to 65 deg and get a fire going in the ...
Mjack7's user avatar
  • 1
1 vote
1 answer
1k views

How to set Nest Thermostat to control blower without heat

I have a Lennox G14Q3 propane furnace (forced air). I used the Nest/furnace setup last winter without any problems with just the W and R terminals. But, these summer days I would like to push air ...
Josh Jobin's user avatar
0 votes
2 answers
380 views

Lennox G16Q3-50 Furnace with AC, Door Interlock Switch and Main Circuit Breaker

If the door of the Lennox G16 is removed, thus the door interlock switch unpressed and system off. Does this mean that I only need to shut off the AC power from the outside breaker panel and leave the ...
user3108698's user avatar
2 votes
1 answer
3k views

How to add C wire to a very old 2-wire Lennox G16 Gas Furnace?

I recently bought a Sensi Thermostat with Wifi to replace my vintage one. I thought it would work with my 2-wire heat only system because it has batteries , but found out that using the Wifi feature ...
LennoxG16's user avatar
0 votes
0 answers
157 views

Furnace not working

I came home to my furnace having no power even to show trouble codes. I turned off my breaker opened the blower door and it had a blown 5 amp fuse on the curcuit board. I replaced the fuse turned the ...
Billy Korsen's user avatar
0 votes
1 answer
119 views

What would make my Lennox gas stove just shut off and the pilot light goes out as well?

We've tried cleaning it and restarting the stove still doesn't seem to stay on.
Kayla's user avatar
  • 1
0 votes
3 answers
22k views

My lennox furnace has no filter

I searched for 30 minutes, and I could not find the furnace filter, is it possible to install/build a filter slot? my whole family got allergy after turning on heater this winter. Thank you! Lennox ...
user2418709's user avatar
0 votes
1 answer
3k views

What could be causing my Lennox furnace to blow cool air?

My Lennox outside furnace is blowing cool air, not hot even when the burner is lit. It takes 3 times longer to heat the house than it should. I just had the draft motor replace about a month ago and ...
Mike's user avatar
  • 1
1 vote
1 answer
9k views

how to change furnace filter (bottom return) for Lennox G43UF

I have a Lennox G43UF furnace and I am not sure if I need to have both a filter for a side return and bottom return. If I do (which sounds logical), where would the location of the bottom return ...
dizzy's user avatar
  • 19
0 votes
1 answer
11k views

How well does a single A\C unit provide 2 zone cooling?

My 2,900 square foot house currently has two separate AC systems (one upstairs, one downstairs). They're both very old and need to be replaced. One of the four HVAC salesman that provided quotes ...
user249493's user avatar
1 vote
4 answers
28k views

Why is my Lennox g40uh series furnace not turning on?

I have a Lennox g40uh series furnace and it just stopped working today. I can reset the furnace and can see that on the control board both LEDs (green and red) are blinking together which indicates ...
Crackerjack's user avatar
8 votes
9 answers
27k views

Where should my furnace filter go in a Lennox G40UHX series furnace?

I have a Lennox G40UH(X) series furnace, which is installed in our attic (We have a single-story house on a slab). Because the furnace is installed in the attic, it is "laying down" on its side, and ...
Jared Harley's user avatar
  • 1,363