The furnace is part of an HVAC or central heating system used to generate heat. Typically this is done with gas, a heat pump, or an electric element. For hot water and radiator based heating, use the boiler tag.

learn more… | top users | synonyms

0
votes
2answers
75 views

wiring in a electric furnace to electrical subpanel

I have a 30 amp double breaker in my main home panel feeding my detached garage 100amp sub panel. Can i run a electric furnace with a 90 amp breaker in the subpanel. Or is this setup all wrong
0
votes
1answer
62 views

Furnace Fuse Blows Immediately

This afternoon, our Ruud furnace suddenly stopped working. After poking around a bit, I realized that the 3A fuse on the control board had blown. I ran to the hardware store and replaced it, but no ...
0
votes
3answers
1k 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 ...
0
votes
3answers
217 views

Closing off heating ducts

We have a natural gas furnace that currently heats our entire 2400 square foot home. We plan on putting in a rental suite in the basement which will require closing up all the duct work into the suite ...
0
votes
4answers
338 views

Is it safe to use an HVAC system even though the duct wrap contains asbestos?

In our rental house the furnace ducts are very dirty. We brought an expert to clean it, but he said he just won't do it because the tape around the ducts (in the attic) is probably asbestos. After ...
0
votes
3answers
30 views

Can't select some temperatures with the thermostat of my furnace

I have a problem with the thermostat of my furnace. This problem is wired but I'll try to explain it as clearly as possible. When I turn the button of the thermostat, some temperatures can't be ...
0
votes
2answers
1k views

Should I replace my Pressure Reducing Valve?

A few weeks ago, my oil-fired water boiler started continuously leaking water out of the pressure release valve on the top of the unit. I know this is leaking steadily because it drains into a 5gal ...
0
votes
2answers
101k views

How can I test whether my furnace issue is the limit switch or the thermostat?

I suspected this issue during the winter and confirmed it now in the summer. Regardless of the temp in my home, the blower motor runs non-stop. In the winter this must have been causing my home to got ...
0
votes
2answers
61 views

How to move from RH/RC thermostat to C thermostat in AC only system?

I see this is a pretty common question, but the answer seems like it might be dependent on your thermostat and air handler, so I'm posting with my specific questions. I'm upgrading from a White ...
0
votes
1answer
105 views

How do I wire my furnace humidifier so it comes on any time the fan is on?

I have an Aprilaire 600a humidifier from a few years ago and currently it's wired into my furnace with two control wires labeled "W/G" and "Cf". The "W/G" is connected to the W terminal on the ...
0
votes
2answers
35 views

Furnace fan runs all the time

our furnace fan runs all the time It doesn't switch off when the furnace does and keeps blowing cool air I've replaced the filter and it's still running The thermostat (RTH6400D) isn't set up to ...
0
votes
1answer
52 views

Pilot lights, but main burners don't on furnace with no flame sensor

I have a Rheem furnace in my house. It recently stopped working. It is the type where the pilot is not always on. Anyways, the ignition will kick in, and the pilot lights just fine. However, the ...
0
votes
2answers
69 views

Are my heat pumps using the right amount of power?

I'm trying to figure out if our two heat pumps are being power hogs and if there is something to do about it, or if they're operating normally. We bought our home recently and haven't been in it but a ...
0
votes
2answers
69 views

Replace or wash this furnace filter?

My mom's furnace has ductwork until right next to the furnace, where the return air instead goes into an obsolete electronic air cleaner that is basically as big as the furnace itself. The issue is ...
0
votes
1answer
84 views

Thermopride OL5-85 oil furnace no longer works

We bought this old house where the oil furnace worked for a while. Now it does not work even after adding enough oil and priming the furnace. We have already pushed the reset button..so I do not dare ...
0
votes
1answer
49 views

Should there be a cap next to my furnace ac drain?

In the picture below, the left side has a good amount of airflow while the ac/blower is running. The tube on the right is the drain that the condensation flows out of to the floor. Should there be a ...
0
votes
1answer
29 views

Gas frunace trouble shooting

Blower kicks on early and will only run 1 cycle. Have to turn down thermostat and turn it back up again to get furnace to come back on. It is gas.
0
votes
2answers
241 views

Can I remove a furnace compartment vent that's obstructing roof repair?

There are two vents going up to our roof, one is the normal vent from the furnace exhaust straight up to the roof. But right next to it there's a second vent pipe, a little larger and single wall. ...
0
votes
2answers
123 views

HVAC system setup

I have a builder building me a home right now and we had agreed to set up two separate heating and cooling systems for the first floor and second floor of the house. I raised the issue the other day ...
0
votes
1answer
308 views

Condensation at roof, down outside of furnace/water heater vent. What is happening?

I am getting condensation dripping down the outside face of my furnace vent at the roof. I think I know why this is happening I'm just curious how to remedy it. There is a cast iron exhaust pipe that ...
0
votes
1answer
2k views

Does the pilot flame of a gas furnace stay on for the duration of a heating cycle?

I was looking at my furnace a couple of days ago and I notice one thing: there is something red hot there where the spark igniter and the thermocouple assembly is. I can hardly see it and I am not ...
0
votes
1answer
79 views

If flame sensor will affect Motor assembly's functionality of furnace? How does that work? [closed]

I have two Air conditioning company. A is the self-hired for my A/C, and B is assigned by home warranty company. This summer, the technician with A came out for an annual maintenance on both A/C and ...
0
votes
1answer
6k views

gas furnace pilot light is lit,,won't produce heat, making a clicking sound,,,

my gas furnace isn't producing heat the pilot light is on and it's making a clicking sound what can I do? I've tapped the flame rod.
0
votes
3answers
7k views

Why does my furnace drip bucket fill up so frequently?

We have an oil furnace that heats the house using a two-zone hot-water circuit, and also acts as an on-demand hot water heater. There is a pipe coming off the collection of pipes coming out of it that ...
0
votes
1answer
264 views

How can I prevent my furnace exhaust pipe from freezing?

My furnace keeps on turning off because my air intake freezes. The reason it freezes up is because my neighbors exhaust vent blows directly on it. What can I do to prevent this?
0
votes
2answers
4k views

Why doesn't the “fan on” mode work after I installed a new thermostat?

We moved into a new house. I installed a new Hunter Thermostat. I have a furnace only and the old thermostat only had 3 wires connected. SO I connected those three wires (G, RH and W/B). The ...
0
votes
1answer
821 views

Which way should furnace filter face?

I replaced my furnace filter (every 30 days) but upon Googling, I've found it has to go certain way. It's suppose to go the way where the arrow points for the airflow. But my filters have no arrows on ...
0
votes
1answer
351 views

How close can an electric water heater and an electric furnace be to each other?

How close can an electric water heater and an electric furnace be to each other? My water heater is 7 inches from my furnace. I need 4 inches so that I can install a water softener and wash sink. So ...
0
votes
2answers
306 views

Would a failing igniter cause my furnace to blow cold air?

I noticed tonight my furnace was firing up, but not actually blowing out heat. I turned the thermostat down so it was no longer triggering it, let it sit for a couple of minutes, and then turned it ...
0
votes
1answer
172 views

Legal requirements regarding 100% asbestos duct work [closed]

I am renting a condo. After starting the heater, dusty air came out of the registers, so I called out a company to clean the ducts. They verified the ducts are 100% asbestos and cannot be cleaned. ...
0
votes
2answers
347 views

Furnace control board - interchangeable?

A few months ago, I had someone working on my outdoor a/c unit, and he accidentally shorted out the control board in the furnace (it's a Goodman gas furnace GKS91155DX). He replaced the board, and the ...
0
votes
2answers
17 views

Furnace blowing cold air

Furnace wont produce heat. Thermostat is brand new. It Will work fine for a minute then heat come on go right back off. Can't find where filter goes house is old and vents are dirty I thought it's the ...
0
votes
2answers
28 views

How much difference does hot vs cold air make with regards to an Aprilaire 600 furnace humidifier evaporation rate?

If I run the humidifier only when the heat is on, I get good evaporation. However, I want to consider also running it with just the fan running because our furnace doesn't run all that often. Will I ...
0
votes
2answers
57 views

Furnace keeps kicking off and on

My furnace runs for a few min then flickers and shuts off and then the system recycles and it fires back up and the process repeats over and over and over etc....
0
votes
2answers
144 views

Very old, Coleman, through the wall (double sided) mounted gas heater not working

My home was built in 1957, I had a new heat pump system put in (which I now hate) 7 years ago. It works fine in the summer, but in winter it doesn't heat the house very well. At the time, I kept the ...
0
votes
1answer
82 views

How to wire a C-wire from a humidifier to a Carrier furnace?

I need guidance on a wire. One wire connects the humidistat to HUM. Another wire should go from the humidifier to COM24Vac. My COM is taken as you see in the picture. Is it an issue to wire the second ...
0
votes
1answer
44 views

question about a gas furnace having to light repeatedly

I am new to this forum, but I will do my best to answer any questions I can (I am a general contractor with a background in engineering and residential construction and machine design) so, here is my ...
0
votes
2answers
171 views

Rain water leaking around attic furnace

I bought a house a few months ago and when I bought it I noticed what appeared to be a water spot on the ceiling of the top floor. Of course I didn't do anything about it until heavy rains over the ...
0
votes
1answer
76 views

Cant I just use a 24v wall instead of a tranformer?

I can just use a 24v wall transformer that I have plugged into my sprinkler system and use that in place of the transformer on my electric Central coleman furnace right? I would connect the hot line ...
0
votes
1answer
45 views

How do I switch the furnace to heat mode?

I have an older good Sears furnace. It was on cool mode this summer and the fan could come on. I can't find how to switch it back to heat mode! Thanks. Linda
0
votes
2answers
253 views

My goodman furnace is not igniting my burners

I have a goodman furnace and when it is calling for heat the ignitor comes on and goes off and comes on again and the burners never comes on what could be the problem
0
votes
1answer
272 views

Furnace reaches temp, shuts off but wont come back on

I have an American Standard furnace (natural gas)with a manufacture date of 2004. The thing won't come on unless I power it off (have a switch right beside it that serves this purpose), let the fan ...
0
votes
1answer
111 views

What is this 6" vent coming out of the main furnace trunk going under my deck for?

I have a 6 inch round duct that comes out of the main trunk about 5 feet from the furnace. It runs through the basement and outside the house (under the deck). What is this? The furnace also has 2" ...
0
votes
1answer
284 views

Where is my Common Wire? [duplicate]

I purchased a wifi thermostat and cannot located the common wire. My unit is old and is a Coleman 70 with no terminals inside labeling the wires. As you can see in the second image, there is a ...
0
votes
1answer
71 views

Amana Furnace 90% eff. need help

Furnace will run for half a day to a day producing heat, then it will stop producing heat but the furnace will try to run still blowing air. Also, if I flip the switch off and then back on 10 seconds ...
0
votes
1answer
548 views

Can a gas furnace be installed in an outdoor enclosure?

I have an old home in which ductwork has been retrofitted. The ducts for the first floor are arranged under the floor. The first floor is heated and cooled by an electric package unit sitting just ...
0
votes
1answer
312 views

Is it normal for the burner in my furnace to turn on and off during a single heating cycle?

During the heating time when the furnace is running to reach the temperature ask for, the burners will run for 3.5 to 4 mins.than shut off for 1 min. Then turn on again.it will do this until temp. is ...
0
votes
1answer
917 views

Carrier 60,000 BTU 92% Furnace vs Carrier 40,000 BTU 95% AFCU Furnace

I have about 900 finished square feet in my house, and I'll eventually be adding another 200 or so finished sq/ft in my basement. I'm looking to get my furnace replaced and have been quoted two ...
0
votes
1answer
117 views

Possible to check NEST system compatibility by looking at current thermostat model?

I'd like to replace my Honeywell CT87A thermostat with a Nest thermostat. I see that Nest has a page to check system compatibility. Is it possible to identify if my system is compatible without taking ...
0
votes
3answers
336 views

My furnace cycles once, then won't ignite again. What could be wrong?

My furnace is not working properly. I shut down the whole electricity and also the switch on my furnice and waiting a few minutes to turn all back on. It will heat up the house and turns off ...