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

2
votes
2answers
646 views

Furnace Draft Inducer Repair: is previously installed back plate necessary?

I'm replacing a non-functioning draft inducer on the Goodman furnace in my house (GMP075-3). The previous inducer was mounted with a sheet metal back plate between it and the wall of the furnace. ...
2
votes
4answers
11k views

How do I wire an old furnace motor so I can use it as a garage exhaust fan?

Since last I posted, I moved WAY south (lil warm down here) and the house I moved into was a foreclosure so a few things needed done, namely the AC and furnace. When the guy did the job he said he ...
2
votes
0answers
268 views

Why won't my condenser turn on when I run my heat pump?

I have a York Affinity condenser. When I run my heat pump, I expect it to turn on somewhere in the cycle but it doesn't. It generally does this once a year. The usual fix is to cycle the power of the ...
2
votes
0answers
212 views

How do I know if my high limit and low limit are set correctly on my aquastat?

I have a boiler that is only providing heat for my forced hot water baseboard system (4 zones). I've always thought that the high limit on the aquastat was too low (the temperature on the boiler ...
1
vote
2answers
6k views

How do I build a firewall around my furnace/water heater?

I'm in the planning stage of finishing my basement. I'd like to section off the furnace and water heater, and am assuming that I should fireproof that section of the build. What's the best way to go ...
1
vote
2answers
1k views

Is there a filter-reminder thermostat that uses run-time instead of total time?

My HVAC filter is in my crawlspace and is a hassle to change. I don't want to change it more than needed. "Change it every month" is bogus advice because in some months (like May) we don't have to run ...
1
vote
2answers
688 views

What could be wrong with my furnace?

The furnace started blowing cold air so I checked the furnace and the burners weren't lit only the pilot was on. This happened last year and repairman said that if it got too hot would trip a sensor ...
1
vote
2answers
39 views

Do natural gas furnaces have internal breakers?

I rent a house with a natural gas furnace. The furnace was not working at the beginning of this winter, and so we called the landlord to fix it. The landlord hired a repair man, who came and noticed ...
1
vote
4answers
1k views

Are 5" thick filters for furnace/Central AC still available?

My furnace/AC was installed about three years ago. It uses 16" X 25" X 5" filters. The problem is when I try to find a replacement at my local home center: at Lowe's, Home Depot, (you name it), I ...
1
vote
2answers
188 views

How do I choose a furnace airfilter?

I have a furnace/air-conditioner that can support filters of various thicknesses: 1", 2", or 4". Filters are available in various MERV ratings. How should I decide which filter to use?
1
vote
2answers
55 views

Very old furnace- I need a technician to inspect it-What would be a good check up list?

First of all you should know that this is about a 25 years furnace that is very simple and that if nothing is wrong with the heat exchanger it should last forever since, IMHO, the parts are very ...
1
vote
2answers
2k views

Why is my furnace blower coming on so early in the ignition process?

Alright, I installed a new furnace a few months ago and have begun to notice an issue with the blowers. When the furnace first starts up, the exhaust blower should turn on to expel gas, then the ...
1
vote
2answers
63 views

Which furnace thermostats support variable swing/deadband?

My home furnace is currently controlled by a programmable Honeywell thermostat, but it regularly thrashes the furnace by turning the furnace on for just ten or twenty seconds. It seems that the ...
1
vote
1answer
33 views

Why are my radiators leaking?

I have a gas boiler that seems to have way too much water in it and has pushed the excess water out the vents on my radiators. I have shut it off. It has flooded my main floor. How do I stop this?
1
vote
1answer
3k views

Which way does the air flow through my furnace?

Below is my furnace and I need to change the filter however I am unsure which way is the airflow direction. Red or Blue?
1
vote
1answer
16k views

Gas furnace kicks on then off frequently

A few times in the past week I will wake up to my furnace turning on, hearing a click when it tries to ignite, then turn off. This will happen for a couple minutes before the furnace quits trying. ...
1
vote
1answer
252 views

Can I reduce the size of my hot water heater vent or direct the vent out the exterior (house has high efficiency furnace)?

The shower in my master bath is tiny. When I removed some dry wall to see if I could widen it, I found a large ~10" round vent running through the space(must be the furnace). Now that I have a high ...
1
vote
1answer
260 views

Is it safe to put a gas furnace in the same room as an electric clothes dryer? [duplicate]

Possible Duplicate: Can an electric dryer be next to the gas furnace? We are currently remodeling our house. Is it safe to put a gas furnace in the same room with an electric clothes dryer? ...
1
vote
3answers
14k 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 ...
1
vote
1answer
57 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 ...
1
vote
1answer
426 views

How can I connect a humidifier to a Goodman dual fuel heating system?

Purchased a dual fuel goodman system with CTK04 comfortnet thermostat. The thermostat installtion guide shows wiring of a humidifier to the (2) Hum terminals on the furnace IFC. My furnace model is ...
1
vote
1answer
90 views

What could cause my old gas furnace to keep cutting out?

I have a old gas furnace that keeps cutting out. It turns on and the when it hits the temp it turns off and then when it turns on it will not give it gas. It will just sound like it blowing but no air ...
1
vote
2answers
128 views

How can I safely put a plug on an old furnace motor that has just two wires

My Old furnace motor has just 2 wires, Black and white. How can I safely put a plug on it to use it? I want it to power a chicken plucker.
1
vote
3answers
7k views

How do I wire a humidifier without a 24 VAC IN terminal?

The instructions for the humidifier I'm installing says to connect the humidistat wiring to the two terminals "marked 24 VAC IN". My furnace doesn't have terminals marked that. I have R,C,W,Y.G. Am ...
1
vote
1answer
4k views

How can I figure out why the low voltage furnace fuse blows on heat but not cool?

I have a Tempstar Model NTC6100KFG1 gas furnace. Furnace was working fine through the summer blowing the AC. It's been off for a month or two as we've been changing seasons here. When I went to turn ...
1
vote
1answer
215 views

Replacing Oil Furnace with Heat Pump

My wife and I would like to remove the older oil heat from our home and replace it with a heat pump. We currently have an Amana central air conditioning unit (3 ton), and an oil furnace in the ...
1
vote
2answers
328 views

How do I interpret my furnace clearance diagram?

My brother-in-law and I are going to be finishing my basement. We just got the permit from the building inspector. When they returned my plans there was a note that told me to make sure furnace and ...
1
vote
1answer
4k views

Why does my pilot light go out continuously?

My furnace pilot light keeps going out. 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 come back on. Could the thermostat be ...
1
vote
2answers
810 views

Why won't the heat shut off in one zone?

we have a three zone baseboard hotwater furnace. a few months ago one zone would randomly stay on, we did change the thermostat we have not noticed the problem again, but in another zone we have the ...
1
vote
1answer
528 views

Furnace Airflow

I have central air. When the furnace comes on, we can feel air coming out of the registers for a few minutes, then the airflow stops. If we turn it off for a few hours, we can turn it on again and get ...
1
vote
1answer
283 views

Massive reduction in air flow in furnance with air filters

After I put in a 3M filter into my furnace the air flow was massively reduced. So, does that mean the filter is wrong or something is wrong with my furnace.
1
vote
2answers
98 views

Wiring Aprilaire 700 Humidifier to York TG9* Furnace

I've read the related posts, but they don't answer my questions. Please, help! We had contractors installed: * Aprilaire-700 Humidifier with Auto/Manual Humidistat-Control Knob (non-digital) * ...
1
vote
2answers
87 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 ...
1
vote
2answers
60 views

How do I calculate how long a furnace has to work to compensate a given temp drop?

I am trying to understand the dynamics of heating a home after the furnace size was calculated. Say you have a 60000BTU furnace to heat a 2000 sqft home. At the beginning of the heating season you ...
1
vote
2answers
217 views

furnace blower motor vibration when working hard

A few weeks ago my furnace developed a vibration that can be heard throughout the house. If I remove the side panel of the furnace or if I remove the filter, the vibration goes away. My theory is ...
1
vote
1answer
54 views

How do you troubleshoot a baseboard heater that is not heating up?

I have baseboard heat and we are not getting heat on one room. Can't bleed air from the baseboard itself. How do I troubleshoot the issue?
1
vote
2answers
102 views

Blower fan speed selection

I am reading a book about HVACs (not finished yet,I might find my answer down the road) and they say that you can increase the speed of your blower (well ..you can adjusted) to obtain the airflow you ...
1
vote
3answers
239 views

Running computers in basement storage room safely

I have kinda an odd one. I'm mostly concerned about fire safety here and am not concerned about power, I already know how to handle that properly. I have a somewhat large basement with an unfinished ...
1
vote
3answers
14k 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 ...
1
vote
1answer
179 views

Why does my Thermo Pride oil furnace need constant restarts?

We have a Thermo Pride oil furnace that requires frequent restarts to run. We just purchased the house and had the annual service/safety check completed as it was neglected for several years. When the ...
1
vote
1answer
202 views

What to do first in a house with poor thermal performance and high energy bills

I just moved into a house and am a little bit disappointed in its thermal performance so far. It's winter and cold outside, and the furnace heats the house up pretty quickly, but then the house gets ...
1
vote
1answer
6k views

Forced air system blowing cold air through bedroom vents, hot through the rest

I'm in a rental house for the next few months which hasn't been particularly well maintained. It does have a newish looking Goodman gas furnace, yet the gas bills seem outrageous to me ($250 per month ...
1
vote
3answers
614 views

Should I leave the fan switch on my thermostat set to fan rather than auto?

I purchased a new Amanda Furnace in Oct'2013. I am told in order to maximize a warm, consistent room temperature I should set the thermostat to the Fan position rather than the Auto position. Does ...
1
vote
2answers
280 views

How do I close this hole in the HVAC vent?

What's the best way to close up this hole in the venting leaving the hvac? Would foil tape be sufficient? Right now it bleeds out hot air into the basement in the winter, and cold air in the summer. ...
1
vote
1answer
1k views

Furnace won't adjust to thermostat setting

I have a 2007 Trane furnace that has been working the AC all summer just fine. With the cooler weather, when I turn on the heat and set the thermostat to 72 degrees, the furnace comes on but heats the ...
1
vote
1answer
2k views

Why is the circuit breaker for my furnace stuck in the off position?

The breaker for my furnace is stuck in the off position. We were away for the winter and had someone shut it off, and now the breaker won't turn on at all. We shut off the thermostat upstairs thinking ...
1
vote
2answers
887 views

furnace creating a ground?

our gas furnace has a junction box on the side of it for the 110 feed for the blower, the feed has no ground wire , if i put a meter on the hot wire and metal box i get 110/120 , without a ground wire ...
1
vote
2answers
8k views

How do I test a furnace limit switch?

When my thermostat reaches the desired temperature, the furnace fan shuts off briefly, then cycles on and off a few times. Several internet posts pointed me to the limit switch, which seems to make ...
1
vote
1answer
17 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 ...
1
vote
1answer
31 views

my furnace fan stays on even when at temperature

I recently installed a 2nd generation NEST thermostat. I'm not home very often, but I was paying particularly close attention to the furnace after installing this thermostat and I noticed that the ...