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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.

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1answer
18 views

Furnace Fan (Heat Pump) having issues when starting sometimes with a buzzing noise

We have a Central Electric Furnace model # EB12B. It is paired with a heat pump. We noticed the issue when we were running the A/C this year and is has continued while running the heater. When the ...
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1answer
36 views

Furnace Pressure Switch Testing

I have a ComfortMaker combination furnace/AC for the back part of my house. The furnace kicks in, but never heats up. No errors are reported. Started troubleshooting and took a peek at the pressure ...
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10 views

Heating, and furnace making noise

Why does my Goodman gas furnace sound like a jet plane when the burner kicks on.My fan kicks on first,then the heat comes on,but sounds like a jet firing up.
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63 views

Is my furnace limit switch tripping due to a flawed coil installation?

I have two furnaces - one for each floor. One of the furnaces that were replaced within a year keeps blowing cold air randomly. I would reset it by turning the main power switch off/on and then it ...
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1answer
2k views

Blower motor turns on before furnace heats up all the way

I have a Honeywell furnace and when it starts the exhaust fan kicks on then the flame starts (it's a propane furnace) it warms up between 30 seconds to a minute then the main blower kicks on but it ...
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1answer
61 views

Home furnace not kicking on or staying on

I have a furnace question. Our house has an Amana furnace and it won't seem to kick on. For context, the temperature in the house is around 60 degrees or so. When setting the thermostat higher, a ...
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6answers
29k views

Low voltage fuse blowing in furnace

I have an outside A/C compressor and indoor furnace fan combo in the attic. The unit was off and the 3 amp fuse was blown. I replaced the fuse and used the thermostat to turn the fan on followed by ...
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1answer
78 views

What is causing intermittent furnace ignition failure? How to Diagnosis?

I have been researching how to diagnose this intermittent lighting issue with my furnace but the common issues do not seem to apply. Blower turns on Ignition coil turns cherry red Sound of gas blower ...
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2answers
3k views

Furnace keeps going out during cold periods, needs procedure to reset

I have had a reoccurring problem with my Rheem gas hot air furnace. Model# RGVC 07EA ER and SER #KN5D1041F47889671. This is a 28 year old furnace that is a horizontal attic mounted furnace. I have had ...
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3answers
77 views

(SOLVED) What is a whining, high pitch sound coming from my furnace when heat kicks in

EDIT: SOLVED. IT WAS THE FLEX CONNECTOR. THANKS EVERYONE. My gas furnace makes a high-pitched whining sound when the burners turn on (when I can see fire). A repair man came and told me it may be that ...
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0answers
19 views

Gas furnace ignites but then makes large knocking sound

My gas furnace will ignite, but after the pilot goes on for a moment it creates a large periodic knocking sound over and over again instead of the fan starting. I have my suspicions, but I wanted to ...
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4answers
35k 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 ...
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18 views

Tempstar 2 stage furnace restarting every 7 minutes - not going into high

I have a tempstar 9MPT model based furnace. Also sold under a number of other brands - comfort air, etc. It is a two stage heating with a PSC motor high efficiency furnace. After about 7 minutes of ...
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1answer
57 views

Wall furnace burner not starting

My wall heater is not functioning. I had a similar post last year, and this year the problem evolved. Attached is the kind of wall furnace that I have. https://drive.google.com/open?id=...
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4answers
138 views

Considerations for installing a high efficiency furnace in my attic?

I live in Upstate NY and in the winter it gets below 0° F. I currently have baseboard water heating throughout my home. Prior to this I believe there was a gravity furnace which supplied the house ...
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1answer
50 views

What could cause the blower of a Coleman furnace to come on all by itself?

I have a Coleman furnace in my mobile home. It was really hot today and the furnace blower came on all by itself. It has ran for 7 hrs. and wont shut off. How do I fix this and what is the problem?...
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2answers
6k views

No C (Common) terminal on Furnace.

I am trying to hook up a new wi-fi thermostat. I currently have 4 wires running, but there are many unsued that are terminated in the jacket of the wire. No issues there. However, when I ...
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2answers
28 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 ...
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0answers
21 views

Thermostats with or without variable temperature differential (swing)

I am looking at replacing my thermostat, and don't really need or want one with geosync. I am thinking of the honeywell RTH9585wf. Currently I have a lux that is not wifi but programmable. It ...
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1answer
591 views

No power in r line after changed thermostat

I have a carrier furnace 2008, just changed my old thermostat to new nest thermostat, forgot to turn off the power. Now I have no power on my r line, checked short fuse still good, red light in front ...
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0answers
30 views

Water Dripping From HVAC Furnace PVC

I have 2 PVC pipes coming out of my TRANE gas furnace. Today I noticed that one is dripping water from the top. Picture attached. Its a slow drip. What could this be?
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1answer
220 views

Ecobee3 Setup and furnace only has W G R

My existing thermostat has 4 wires (missing C) so I'm attempting to use the Power Extender Kit (PEK) at the furnace control board. Only problem is, I only have 3 wires that are obviously labelled at ...
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2answers
473 views

Is the ventilation in my utility closet a construction mistake?

With colder weather here in Northern Colorado (down to 22° F) my Goodman 90% efficiency furnace (GKS90453BX) came on for the first time in the (ca. 2005) home that I recently moved into. The furnace ...
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1answer
44 views

My blower fan won't turn on unless AC is running

So first of all, I've changed nothing: same thermostat and same everything. I typically run my blower fan 24/7, but a few days ago it stopped working unless the AC is on. Which tells me that the ...
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2answers
91 views

Pilot light keeps going out

I have a Coleman mobile home furnace and my pilot light keeps going out. I have replaced the thermocouple twice, cleaned the orfice, replace the gas regulator with a brand new one, and even crawled ...
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1answer
158 views

Why would my Maytag FG6RC high efficiency furnace restart in the middle of a heating cycle?

My furnace is probably 7-8 years old, and this heating season the furnace has developed a strange problem. The furnace starts normally, but before the temperature reaches the thermostat setting the ...
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1answer
47 views

Adding split AC to a Dayton oil fired forced hot air furnace

I'm trying to add split central air to my Dayton oil fired forced hot air furnace, mod # 3E268A. The manual clearly says it can accept this but the terminal block in the unit only has (4) lugs. TT and ...
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2answers
19k 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 ...
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1answer
7k views

Goodman gas furnace limit switch opening, blower only runs with a/c

I apologize in advance for some of my incorrect terminology. My father has a 2004 Goodman GMH80904BN gas furnace with a/c. The a/c has functioned properly all summer here in Ohio, we have recently had ...
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2answers
391 views

Furnace Blower fan doesn't start

I have a keeprite high efficiency furnace that Was a part of my new house. It's 2016. The Honeywell thermostat is set at 23 deg C. This is what happens when the temperature is below the cut-off I ...
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2answers
35 views

Oil burner runs for at least one cycle then safety locks out

I have an older Slant Fin Liberty oil furnace that safeties out sometime around 4 hours. It seems to be intermittent because I have seen it do more than one cycle. The recent history on it is about a ...
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1answer
19 views

How do I purge the air from a hot water furnace with zones

I want to try and bleed the air from my hydronic ( baseboard ) heating system. It's a natural gas system, I think I understand the basic functionality but my system seems to be a bit unusual and I'm ...
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1answer
867 views

Honeywell VR8300A3500 Single Stage Heat Gas Valve to Ecobee3 with C wire

Hey everyone have a quick question regarding a honeywell VR8300A3500 Single Stage Heat Gas Valve and the introduction of a Ecobee3 wifi enabled thermostat with a "C" wire. just want to make sure i am ...
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2answers
15k views

How to address loud cold air return

The cold air return on my forced air furnace is too loud. While it is is tolerable, there is a noticeable sound of rushing air when the furnace is running (not a whistling sound, just a blowing sound)....
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1answer
885 views

Low speed furnace fan blower motor will not shut off

I have a carrier furnace that has a low speed fan blower motor that will not shut off no matter how long I leave it running. I checked that removal of the G wire at the control board does not change ...
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1answer
67 views

Rapid on/off cycling of furnace

My 50-year old wall furnace keeps cycling on and off as it gets near the set temperature. Can I fix this by changing to a new thermostat? It's a 2-conductor cable (no blower).
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2answers
65 views

How to troubleshoot gas supply not making it to some appliances

I recently purchased a home and once utilities were turned on I've been having issues with certain gas appliances. Some appliances required a normal amount of time to get the gas flowing after being ...
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1answer
81 views

Neighbor's furnace exhaust

My neighbor's house sits 20ft from mine. Their furnace exhausts out the side of their house about 3 ft above the ground. The exhaust is blowing onto the side of my house and into the attic vent. ...
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1answer
79 views

Wiring AC condenser to Furnace

Hello So this is what I was left with I am trying to tie in fan on/off and a AC condenser I have 2 wires for my limit switch, 2 wires from my 24ac transformer, 2 wires from my AC condenser and 2 from ...
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2answers
2k views

Goodman gas burner not lighting

Goodman warm air gas furnace. Gas burner would not light.Status code light blinked continuously. Igniter glows red hot. I cleaned flame sensor with fine grade sand paper. Checked transformer line ...
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0answers
24 views

Furnace not staying on

When my heater starts up it will light and run for approximately 5 minutes and then it trips a limit switch, will not relight until I reset switch. What's causing switch to trip?
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1answer
216 views

Unable to locate filter on Gas Furnace

Can not find where the filter for this furnace is. It is a gas Rheem Criterion II. Have watched YouTube videos but none look like mine. Thermostat keeps saying filter needs replacement.
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1answer
1k views

Low voltage wiring of outside condenser & condensate pump

This is my 1st question here, hope someone can help quick since temperatures are rising. This past winter the cage on my furnace was making noise. It was the fan hitting the cage. I took it out and ...
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16 views

Furnace/thermostat require constant power reset/“reboot”

I have an AprilaireProgrammable thermostat attached to York furnace?Ac unit. The set point is usually around 22 degrees, and the room temperature is reading around 20 degrees. The furnace is not ...
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1answer
24 views

Furnace Inducer Whirrs on and off before igniting, works when I tap circuit board

My furnace gets the signal from the thermostat, then about half of the time, the inducer motor whirrs on and off over and over. Sometimes it runs continuously without ever lighting. When I open it up,...
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3answers
1k views

Thermocouple measured okay, but replacing it fixed the problem?

So the pilot on my furnace wouldn't stay lit. I tested the thermocouple with my multimeter and got 29 millivolts which meant it was still working. Assuming I was in over my head, I called the plumber ...
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1answer
114 views

No C Wire Nest Thermostat

I just installed a nest thermostat. The previous thermostat did not have a C wire attached. It G, RC, (RH Jumper), Y and W. When I hooked up the nest thermostat it was short cycling the blower fan ...
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2answers
1k views

Furnace keeps cycling on and off until it's up to set Temp

I have a Philco 80,000 btu two stage with variable speed blower, high efficiency furnace with a two wire thermostat, on/off. The furnace 6.5 years old and when the thermostat calls for heat the ...
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1answer
214 views

My blower motor doesn't have the brown wires for a capacitor

My blower motor only has 3 wires and there's no wires for a capacitor
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1answer
9k views

Pilot won't stay lit after replacing thermocouple

The pilot won't stay lit on my furnace, when I release the button it just goes out. This started occurring after I did some gas plumbing and had to relight the pilot. I suspected the thermocouple ...