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

3
votes
2answers
448 views

How is a high altitude natural gas burner different?

What is the difference between high altitude natural gas burner and conventional low altitude gas burner and why high altitude natural gas burner are needed?
8
votes
1answer
272 views

Should I relocate the HVAC unit in my attic?

I have had a couple of estimates to replace our HVAC system and one contractor says he would relocate the system to a more central location in the attic. One says there is no need to relocate. There ...
3
votes
3answers
6k views

If I turn off the breaker to the Gas furnace will the pilot light go out?

I need to turn off the breaker for the furnace but am afraid this will turn off the pilot light to my gas furnace & I don't know how to relight it. Are any special steps necessary to prevent ...
1
vote
2answers
187 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
2answers
660 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 ...
2
votes
2answers
347 views

Can I move my furnace room ventilation intake closer to my furnace?

I live in a 3 story townhouse with a garage in the basement. Off the side of the garage is our furnace room. The ventilation and exhaust for the furnace goes to the roof. For ventilation (air coming ...
9
votes
4answers
12k views

Does lowering the blower speed of a forced-air furnace lower its efficiency?

My gas furnace has two options for the blower speed: MED, and MED-HI. It had been set on the higher speed, but that was too harsh, so I lowered it to the slower speed. Does that have any impact on the ...
10
votes
2answers
9k views

What does a Summer/Winter switch on furnace air ducts do?

On some of our furnace ducts, there is a switch/valve for Summer/Winter or S/W. What does changing this switch/lever accomplish? Can bad things happen if I forget to switch it? Bonus question: ...
4
votes
1answer
443 views

How can I unbend a bent furnace filter slot?

I recently bought a new home. When going to change the furnace filter, I couldn't get the original furnace filter out of the slot at the last part of the filter (where the cardboard border is). Since ...
1
vote
0answers
322 views

Why is my furnace blowing hot air outside?

So I have been having trouble heating my home. I noticed today that there is a vent blowing hot air outside. It is not the return, chimney or venting. Any ideas other that the builder thought we ...
0
votes
0answers
202 views

How can I provide my furnace with outside combustion makeup air?

I cut a 6" opening in an insulated door into the utility room then installed a 6" metal duct with a plastic exterior vent cover. I put 6" insulated flexible duct on the interior stub and let it hang ...
4
votes
1answer
5k views

Can a washer and dryer be next to a water heater?

I have a GE gas dryer (DSXH47GGWW) that is currently next to an exterior basement wall. I'd like to move it to the opposite wall (shared with the crawl space) right next to the water heater next to ...
3
votes
2answers
11k views

How can I determine why my furnace is not blowing enough heat?

During a cold spell last week when temperatures got down to -23f (-31C) my furnace started showing issues with blowing enough air and the air was not very warm. Last winter it did not have any issues ...
2
votes
1answer
629 views

How can I stop my house from waking my wife up every day in the winter?

I'd like to preface this post with the fact that I'm a complete diy amateur. I may say stupid things, or things that make no sense. Please feel free to correct me as I'm always open to learn. So, ...
1
vote
3answers
8k 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
0answers
369 views

What's causing my draft inducer to stay on?

I have a new, 3-year old, high-efficiency, gas furnace in my home. I recently realized that my draft inducer, which normally kicks on before the burners and before the main blower, is not stopping. ...
4
votes
3answers
3k 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 ...
2
votes
0answers
204 views

Are w1 and w2 both energized during a second stage heat call from the thermostat?

Short version: does two-stage thermostat always close W1 circuit when it closes W2 circuit, or they might be closed independently? Long version: I have two-stage furnace, currently connected to older ...
2
votes
1answer
305 views

Will I see any performance gains if I reconfigure my thermostat to control the second stage of my 2 stage furnace?

Our furnace is a two stage one that was installed last year (a Bryant 80t). When it was installed, it was installed with a thermostat for a one stage furnace. This appears to be because this model ...
1
vote
1answer
2k 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 ...
5
votes
1answer
1k views

How can I avoid cold rooms due to combustion air intake?

I have a newer split level house (2006) with unfinished basement. The natural gas furnace is on the lower level in a utility room that is also laundry and bathroom. There's an enormous 8 or 10" pipe ...
0
votes
2answers
232 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 ...
8
votes
7answers
2k 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 ...
3
votes
4answers
470 views

Is it expensive to switch from an 80% to a 90% efficient furnace, to comply with the new mandate?

I'm told by some HVAC companies via mail flyers and websites (example) that it may be very expensive to retrofit new PVC pipes to update an 80% efficient furnace to a 90% one. Therefore, the logic ...
3
votes
4answers
18k 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 ...
-3
votes
1answer
824 views

why won't my furnace turn off once it reaches the desired temperature

I have a moncrief furnace and replaced the thermostat but the furnace will not cut off once it reaches the desired temperature. What could be wrong?
2
votes
1answer
396 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. ...
3
votes
2answers
3k views

Should my thermostat's blue wire be going to W2?

I've recently moved into my first house and am looking to replace the existing basic thermostat in the home. Here is a picture of how I found it wired: Researching the wires, I've read that ...
2
votes
1answer
2k 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 ...
5
votes
3answers
4k views

Do I need a rain\snow cover on this furnace vent?

Just bought a house that had a new furnace installed this summer. Vent number 1 in the image is for the furnace (2 is the water heater and 3 is sump). As you can see in the image, 2 and 3 both would ...
0
votes
0answers
306 views

Can I manually run the blower on my Lennox G12Q3 furnace?

I have a Lennox G12Q3-120-6 model furnace. Does anyone know if there's a way to manually run just the blower without heat? There are no switches on the outside that I can see (other than the power ...
3
votes
1answer
267 views

Is it normal for air to be leaking from where the drain hose connects to the central A/C unit?

I'm trying to determine if I have a leak around my central AC unit. Basically when the unit is on, I feel cool air blowing outside the "furnace plenum" as I believe its called. If you look at this ...
1
vote
2answers
528 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
827 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
1answer
538 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
207 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 ...
3
votes
1answer
417 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 ...
5
votes
4answers
1k views

Why do I have two parallel gas pipes?

I've got a water heater and a hot water radiator furnace sitting next to each other, both on gas. The strange thing is that there are two parallel gas lines feeding each one of these which come from ...
2
votes
1answer
175 views

Is there a standard length on the PVC furnace pipes coming outside the exterior?

We have a high-efficiency furnace. Two pipes are coming outside the house as expected. However, right now, there is at least 2 feet or more of extra PVC on the exterior showing. Is there any ...
3
votes
2answers
2k views

How do I troubleshoot an electric furnace?

I have a Coleman 3300-9051 electric furnace w/AC. The blower continually runs. Where do I find a repair manual and/or what could be the problem. How do I test it.
1
vote
1answer
250 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? ...
5
votes
2answers
360 views

Is there a way to find out how often your furnace is running?

With winter finally setting in, and being the first year in our new house I would like to put some sort of measurement on how often the furnace is working, before I get the bill. Are there any known ...
6
votes
2answers
718 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?
3
votes
4answers
3k views

Can I connect an outdoor wood stove to my current HVAC system?

How to install a wood stove as an auxiliary heat source? (Main is electric furnace with forced air) I've read this question, it doesn't really answer what I need to know. What I would like to do is ...
1
vote
0answers
206 views

How can I clean out the pressure switch port at the inducer housing on a Lennox G40UH furnace?

I have a Lennox G40UH(x) furnace, but the gas does not ignite, because water may have entered the system while raining, or the the pressure switch port at the inducer housing has just to be cleaned. ...
2
votes
0answers
236 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
201 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 ...
2
votes
2answers
1k views

Is it OK to turn off power to a fuel furnace?

Is it OK to turn off the power to a fuel furnace to replace the thermostat? Will the furnace start back up once power is restored? This is on a new furnace with an old thermostat and fuse panel.
1
vote
2answers
626 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 ...
5
votes
1answer
177 views

Are discount furnaces safe to use?

More newbie questions ;-) The house we're looking to buy has an older furnace that "may be manufactured by the Permier/Consolidated furnace company" according to general inspections. We're in the ...