Currenly on a trip and running A/C and not furnace.The furnace started to make a fan noise and the sound like it's trying to fire the gas.Moved thermostat to off and back and forth to heat with no change the noise is there yet. I removed the 15 amp fuse marked furnace and the noise stopped. Problem solved right ? No the thermostat must run off that fuse because then the A/C does not work.Took access panel off of furnace and can't see any easy fix, that's over my pay grade.I'm thinking to disconnect a wire to the thermostat that controls the furnace? Which one ?Furnace is Suburban Thermostat is Coleman MachThanks for any help

A google search of that thermo should give you the manual and the wiring. If your internet connection isn't good I can do that for you.I'm assuming you've not done that already or you wouldn't be asking us. But it seems like every time I say this, the poster comes back and says he did that.

Might be easier to disconnect the wire within the furnace cavity.

2oldman wrote:A google search of that thermo should give you the manual and the wiring. If your internet connection isn't good I can do that for you.I'm assuming you've not done that already or you wouldn't be asking us. But it seems like every time I say this, the poster comes back and says he did that.Thanks Google turned up its the white wire for the furnace What could be causing this ? Bad thermostat ?Furnace problems ? After turning thermostat off and on and pulling fuse the original problem has stopped. I did give the thermostat a light tap or two can that help or hurt ?Was this caused by the thermostat running on AUTO and not on normal ON position ? Thanks

Sorry, I can't answer these questions. Someone will come along.Many of us have replaced with digital units. You maybe could put that in the projects bin.

2oldman wrote:Sorry, I can't answer these questions. Someone will come along.Many of us have replaced with digital units. You maybe could put that in the projects bin.I agree and replacement is on the short list now.Thanks

Furnace and or thermostat problem | Good Sam Community

2oldman
Explorer II
Jun 28, 2016
A google search of that thermo should give you the manual and the wiring. If your internet connection isn't good I can do that for you.

I'm assuming you've not done that already or you wouldn't be asking us. But it seems like every time I say this, the poster comes back and says he did that.
Mandalay_Parr
Explorer
Jun 28, 2016
Might be easier to disconnect the wire within the furnace cavity.
Mikesr
Explorer
Jun 28, 2016
2oldman wrote:
A google search of that thermo should give you the manual and the wiring. If your internet connection isn't good I can do that for you.

I'm assuming you've not done that already or you wouldn't be asking us. But it seems like every time I say this, the poster comes back and says he did that.

Thanks
Google turned up its the white wire for the furnace
What could be causing this ?
Bad thermostat ?
Furnace problems ?
After turning thermostat off and on and pulling fuse the original problem has stopped.
I did give the thermostat a light tap or two can that help or hurt ?
Was this caused by the thermostat running on AUTO and not on normal ON position ?
Thanks
2oldman
Explorer II
Jun 28, 2016
Sorry, I can't answer these questions. Someone will come along.

Many of us have replaced with digital units. You maybe could put that in the projects bin.
Mikesr
Explorer
Jun 28, 2016
2oldman wrote:
Sorry, I can't answer these questions. Someone will come along.

Many of us have replaced with digital units. You maybe could put that in the projects bin.

I agree and replacement is on the short list now.
Thanks
Old-Biscuit
Explorer III
Jun 28, 2016
'WHITE' wire is for Furnace

Thermostat circuit board shorted-----sending DC to furnace and A/C
jetcare
Explorer
Jun 28, 2016
Coleman makes a direct replacement digital thermostat to replace the analog one you now have. Uses the same wire colors.

Makes the swap easy.
Mikesr
Explorer
Jun 28, 2016
Old-Biscuit wrote:
'WHITE' wire is for Furnace

Thermostat circuit board shorted-----sending DC to furnace and A/C

Thank you
wanderingbob
Explorer II
Jun 29, 2016
What brand thermostat ? On my thermo if on auto setting weird things happen . Every thing fine when on speed # 1 or speed # 2 .
bobndot
Explorer II
Jun 29, 2016
Mikesr, just a thought ,
if the fan comes on, on the furnace while you are running the a/c, i would start tapping the furnace in various places to see if it stops. Then you know, its something on the furnace itself.
A loose wire, switch or solenoid ?

I just noticed 'O-B's" post re: the circuit board and that makes perfect sense.