Questions tagged [furnace]

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.

Filter by
Sorted by
Tagged with
2
votes
1answer
1k views

Heater air intake blows out the flame

The problem I have is the air heater shutting down in windy days and I'd like to figure out how to fix this issue. Here's the setup: The back of the house faces North to an open field which gets very ...
2
votes
1answer
181 views

0v at DC thermostat terminal in furnace

I have an old (mid 80s) Rheem gas furnace I hope will last me through at least one more California winter. It's been known to go down into the upper fifties, so it has its work cut out for it. In any ...
2
votes
1answer
949 views

What type of furnace vent pipe is this?

I need to extend my furnace vent pipe up 2 foot above the ridge of my roof to comply with IBC. So I need to couple this pipe somehow and extend it up. Any idea what type of pipe this is and how I ...
2
votes
1answer
979 views

How do I determine/control which heat source is used (heat pump, oil)

I have a heat pump and an oil furnace for backup. How does the HVAC system know when to use the heat pump and when to use the oil furnace? Specifics: I have a Honeywell TH8320U1008 thermostat ...
2
votes
2answers
3k views

Is it a problem that I have two of each color wires on my Honeywell thermostat?

I am thinking about upgrading my Honeywell thermostat. Every thing I have seen describes / shows a single wire for each color. My current thermostat has two wires connected to each terminal (two green ...
2
votes
2answers
28k views

Is my furnace operating normally?

I just moved into my house and I am wondering if this is normal for a furnace. So I have my furnace set to 68 degrees. The temperature on the thermostat says 66 degrees. The furnace is on, but does ...
2
votes
1answer
100 views

Corroded wiring casing in basement - cause?

I just had our annual furnace tune-up and the guy who performed the inspection gave us a B tag violation because the electrical supply wire to our gas furnace is corroded and copper wiring is exposed. ...
2
votes
1answer
45 views

Is wiring supplying an integrated HVAC breaker a branch circuit or feeder?

Since this air handler / furnace has overcurrent protective devices in it, would my wiring from the panel then be a feeder or branch circuit? I kind of think it would be a feeder circuit. And that ...
2
votes
1answer
55 views

Does lengthy refrigerant line between indoor and outdoor unit affect AC performance and result in higher utility bill?

As part of basement renovation, I am moving the HVAC indoor unit for about 30 feet, which means the refrigerant line has to be extended by same length concealed within basement ceiling. Now, I have ...
2
votes
1answer
67 views

What amp rating fuse should be used for the low-voltage side of the control board in my Goodman furnace?

I have a Goodman furnace (model GMH80803BNBC) (with separate Goodman AC condenser). The specs (PDF) are located online. The control board has stamped on it, next to the fuse (for the low-voltage (24V) ...
2
votes
1answer
61 views

No C terminal on furnace. Workarounds? Possible the AC?

I'm Trying to connect my C wire to install a new thermostat but the furnace doesn't have a C terminal. In my readings on this I found that because I have an AC,I can connect my C to one of the wires ...
2
votes
2answers
158 views

Tempstar (ICP) furnace short cycle (runs 10 -15 minutes) then repeats

I have a tempstar (ICP) furnace put in when the house builder built the house. Model is N9MPD075F12A2. Installed late 2009. This problem only happens with the furnace not the AC. When calling for ...
2
votes
2answers
201 views

How to figure out how to wire a 2 wire furnace to 3 wire thermostat

I have a 2 wire furnace and want to wire a 3 wire thermostat. My red wire is connected to the c in the transformer and the white is connected to the load. It works fine 2 wire but I dont want to mess ...
2
votes
1answer
54 views

Where to connect C wire on older furnace

Upgrading to a wifi thermostat and already have extra unused wire from furnace to wall, just not sure where to connect it at the furnace. I do have central air installed, and assume the blue wire ...
2
votes
2answers
189 views

No C terminal on furnace to connect a wifi thermostat

I have an new Emerson thermostat and would like to connect a c wire so it always has power. I have an extra wire that's not being used, but I don't have a C wire terminal on my furnace. I'm wondering ...
2
votes
1answer
11k views

Ecobee3 not turning on heat, but fan is on

I have an Ecobee3 that has been successfully working (both heat, fan, and AC) for the past 6 months. Recently I was trying to get my humidifier working so I was playing around with some wires, which ...
2
votes
2answers
329 views

Furnace Defective Vacuum Switch

The furnace in my house is having a problem. The furnace overall works well and heats the house fine. The problem is that it cannot turn itself on. There is a Nordyne vacuum switch on it that is ...
2
votes
1answer
1k views

Installation Ecobee3 Smart Thermostat Confusion

So Ecobee' website says my configuration is compatible but after looking at my wires (Im not an AC guy) I have lots of questions as the wiring doesnt just align perfectly. Im assuming because my unit ...
2
votes
2answers
173 views

Should furnace fan run when return and supply are 'backwards'?

Our furnace supply vents are in the middle of the house and the returns are on the outside - which I understand is 'backwards'. When the furnace is running, plenty of hot air comes out, but seems to ...
2
votes
1answer
2k views

Furnace flames run for a minute then shut off

I have a furnace (Model: NUGK050CF01) that has recently been experiencing some weird behavior. The furnace will come on (I can see the flames) and it will run for a little over a minute. Then the ...
2
votes
1answer
1k views

Does this look like a crack in my heat exchanger?

I had someone come in to inspect my furnace and was told my heat exchanger has a crack and the whole system should be replaced ASAP due to carbon monoxide risks. It's 16 years old but I haven't had ...
2
votes
2answers
10k views

Can I run my furnace in fan-only mode without a G wire?

The house I bought has a programmable Honeywell furnace. It only has a 2 wires connected to it - a black wire and a white wire. The heating system is working fine, except that when the heater is not ...
2
votes
2answers
79k views

How far should my wall be from my furnace/water heater?

) we are refinishing the basement and are enclosing the furnace/water heater, leaving a thin 27" door. My water heater sits back beside my furnace and the enclosure is going to be square so I think ...
2
votes
2answers
9k 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 ...
2
votes
1answer
434 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
2k views

Will a single ductless mini-split heat pump be able to distribute its air evenly throughout my ranch house?

I am in the middle of a deep energy retrofit of my house, and a quick-and-dirty online manual J calculation of the projected loads once my projects are completed shows an estimated heating and cooling ...
2
votes
2answers
706 views

What could be causing my gas furnace to make a loud noise?

I have a comfort air natural gas furnace when it call for heat,their is a loud boom noise,could the hot surface ignitor have a crack or needs replacing?
2
votes
2answers
3k views

How do I make my gas furnace throw out warmer air?

I just bought a new house. It has a 2007 gas furnace. The make is a 2007 heil furnace . I would like to know how to adjust the furnace to make it throw warmer air out of the ducts.
2
votes
2answers
7k views

Can I remove the fresh air supply that is attached next to my furnace?

It looks like my gas furnace is already vented but I'm not sure. There are two white pipes from the top of the furnace that are vented outside. The furnace is a Trane XR90. We have cold winter climate ...
2
votes
1answer
848 views

What is a quieter alternative to gas forced air heating?

My small 1BR apartment has an old gas furnace that works great, but costs my landlord too much to insure. He plans to install gas forced air, an in-unit upright furnace. I'd love to suggest a ...
2
votes
2answers
1k 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 ...
2
votes
1answer
12k 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
1answer
346 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 ...
2
votes
1answer
862 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 ...
2
votes
2answers
5k views

How can I tell what kind of heating system I have?

Seems like a simple question, but I've had a very hard time finding a definitive answer to this. I went to the hardware store to buy a replacement for a faulty thermostat and when I arrived and ...
2
votes
1answer
6k views

How do I fix a condensate drain line that froze in my split electric system with heat pump?

I have a split electric system with a heat pump. It looks like my condensate drain line is frozen. I switched to supplemental heat which does not use the heat pump. Is this enough for now? Our ...
2
votes
2answers
5k 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.
2
votes
3answers
618 views

Are High End Furnace Filters worth the cost?

There are many levels of furnace filters. I can get cheap ones at walmart of a few bucks. Then there are ones that cost upwards of $30. I realize that if you have allergies or low immune systems, ...
2
votes
1answer
95 views

Can metal mesh furnace filters be replaced by paper filters?

We have a furnace that has wire mesh air filters, will it function/be safe to replace those filters with paper filters?
2
votes
1answer
308 views

No power coming from c terminal on furnace

I am trying to set up a nest. My system was a simple heat only R/W wire set up. I attached the green wire to the c terminal on my furnace, but no power is being fed from it, or at least the Nest is ...
2
votes
2answers
550 views

Using existing exhaust stack for new furnace

I'm about to replace the furnace in our house. The existing furnace uses a 6" stack through the roof. I know most new furnace installations just use PVC and poke out of the wall at about ground level. ...
2
votes
1answer
85 views

Furnace blower comes on full time when the thermostat is set to Auto

I have a Maytag furnace and the blower motor comes on right away when the thermostat is placed in auto and stays on when reaching the temperature set point and the heat goes off. I have replaced the ...
2
votes
2answers
4k views

Old furnace with no “C” terminal for wifi thermostat

I'm new to this forum and was wondering if I could get some help regarding installing a Honeywell WiFi thermostat that requires a "C" terminal. I currently have an older thermostat that has only 4 ...
2
votes
1answer
250 views

What causes popping in new wood floor when furnace turns on?

I just had new solid wood floors installed and i hear popping where the floor meets my kitchen wall each time the furnace turns on (lasts for about 3 minutes). what causes the popping and how do I ...
2
votes
1answer
410 views

How should the thermostat wires be connected to my furnace?

I have an Amana AMV90704CXBB furnace, and regular programmable thermostat. I took the furnace apart because I have to wash the blower motor wheel. It was covered in construction dust. In order to ...
2
votes
1answer
232 views

Where to connect c wire

I’m installing a new WiFi thermostat that needs the c wire. I ended up running new thermostat wires that contained the common wire but now I’m stuck on where to connect it to the furnace. Can ...
2
votes
2answers
4k views

Trying to set my thermostat to use FAN only for cooling

I have a Bryant 60k BTU gas furnace(about 6 years old) and no AC. I can manually turn on just the FAN or leave it on AUTO for heating. I have the RITETEMP 6025 thermostat. At the moment I am cooling ...
2
votes
1answer
1k views

Can't get 3rd Gen Nest to power fan on Trane XR95 furnace

I have a Trane XR95 furnace and I replaced my original Honeywell Pro 4000 thermostat with a 3rd gen. Nest. I noticed, however, after installing the Nest that I can't get the fan to run on its own ...
2
votes
2answers
788 views

Help with oversized furnace causing short cycle

I have just moved into a new home that had a pretty terrible HVAC system installed brand new by a flipper which has been causing me a ton of headaches. My house is 2000 sq feet, and the furnace is ...
2
votes
1answer
755 views

Very odd gas furnace installation in apartment… How do I change the filter?

Here are some pictures of the installation: http://imgur.com/a/UWSyD This furnace is actually in my unit. It looks like the previous tenant or landlord just jammed a bunch of filters on both sides. I ...

1 2 3
4
5
18