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.

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2answers
15k views

How do I identify the C terminal on my HVAC?

How do I identify the C terminal on an HVAC, furnace, or boiler? If the terminals don't have a screw labeled C what should I look for on the wiring diagram? What steps should I take if a wiring ...
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10answers
16k views

Do thermostat-controlled, auto-adjust HVAC vents exist?

The residential forced-air HVAC systems I have seen are controlled by a single thermostat in one room. One has to manually adjust the vents in order to adjust the temperature in other rooms. Is ...
6
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2answers
980 views

Can an electric dryer be next to the gas furnace?

I intend to relocate my washing machine and electric dryer within the basement. The dryer will then be about 2 feet from the furnace. Is that OK?
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3answers
9k views

What's causing the rumbling sound when my furnace kicks on?

I have a new, 3-year old, high-efficiency furnace in my home. Last year it started making a slight whining noise that was audible during the very first stage, before the blower motor started. No ...
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6answers
27k views

Why does my furnace need frequent power resets?

I have a NOMA Programmable thermostat attached to my furnace. The set point is usually around 21 degrees, and the room temperature is reading around 17 degrees. The furnace is not coming on. ...
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4answers
146 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 ...
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8answers
3k views

How can I audit my furnace?

I want to keep track of when my furnace is on, with an eye to reducing how much energy I use to heat my house. I could compare it with weather data (temperature, wind speed, precipitation). I could ...
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5answers
34k views

How much energy will continuously running a furnace fan use?

We have a bi-level (tri-level? There's a small entry way and utility room, then an upstairs living area and master bedroom and a downstairs living area with bedrooms) in mid-Michigan. The downstairs ...
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3answers
20k views

Why is my furnace blowing cold air?

My HEIL 7000 natural gas furnace has stopped working what are the most likely causes, and how to verify faulty parts? Normal operation routine Thermostat sends "need heat" signal. Exhaust blower ...
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3answers
3k views

How do I prevent harmonic resonance hum in PVC vent of newly installed hot water heater?

I just had a new power vented water heater installed (HTProducts Phoenix Light Duty) in our crawlspace. The contractor that put it in used part of the existing 3" concentric vent from the furnace we ...
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5answers
3k views

How often should the air filter in the furnace be changed?

Does the period of change of this air filter have an affect on the longevity of the heating and a/c system? What is a good rule of thumb to require replacement?
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1answer
516 views

How well would a hydronic furnace work with a gas tankless water heater?

My current heating system (in Ontario) is an oil hot water tank in a closed loop with a hydronic forced-air furnace (Enerzone XAH 68). The water circulates through what is basically a heat exchanger ...
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2answers
13k views

Why won't my furnace turn off?

My furnace is running OK and heating the house. The problem is that I have the thermostat set to 66°F and it does not turn off when it reaches that temperature. I can turn it off manually at the ...
2
votes
1answer
133 views

What is wrong with my gas furnace?

Note: the below was solved. It was a loose wire between the controller and the gas valve (the white wire on the diagram) This is about an old UltraMax Olsen HCS2 81AD gas furnace it looks like this ...
2
votes
1answer
358 views

What could be causing vibration in my furnace?

I have a vibraton in furnace only when flame is lit. Blower motor seems fine. Is this vibration normal? Recently replaced inducer motor. Heat exchanger has been replaced once. Does not appear to be ...
2
votes
1answer
5k views

Why won't my Heil 7000 natural gas furnace ignite?

I have a Heil 7000 gas furnace Model: NUGK100DH12 Serial: L933050100 When we turn it on at the thermostat, the exhaust blower will kick on. We checked to be sure the gas is reaching the unit and ...
2
votes
2answers
39k views

Why does my pilot light keep going out?

My furnace pilot light keeps going out so I changed the thermalcoupler now the furnace will come on and heat up to the degree set on my thermostat, then the pilot goes out and the furnace will not ...
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vote
1answer
21 views

Goodman GM100 Failure to recycle

Our Goodman Furnace Model GM100 Serial# 9412063230 will start up and run but will not recycle after initially satisfying the thermostat. If you wiggle the gray,(ground), wire on the gas valve, it ...
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1answer
61 views

How to determine if my heating & cooling system is adequate for my home?

Is there some kind of calculation I can follow to determine if the heating and cooling system in my home is rated (adequate) for the size of the house? I assume there is some way to say something ...
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2answers
98 views

How do I reduce the noise from my forced air furnace?

We recently had a new forced air furnace and return installed. The unit works great, but the return (which is in an adjacent closet to the furnace closet) is quite loud. What are some solutions I can ...
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3answers
15k views

Adding a C wire to a new Honeywell WIfi Thermostat

I am trying to install a new Honeywell touchscreen WIFI thermostat and need to add a C wire to my terminal inside the furnace (using the help found at How can I add a "C" wire to my ...
0
votes
3answers
7k views

Why isn't the spark gap lighting the pilot on my furnace?

I've got a Carrier 58GS natural draft furnace, which has a spark gap for igniting the pilot. Unfortunately, the spark gap has not been successfully doing its job. The spark clicks away as the gas ...