Furnace repair?

[Gary_602z]

Hello There!
I have a small problem that I hope somebody can help me out with!
My sister has a older (78?) Bryant NG furnace that the blower motor had an internal short on. I had to have a new motor put on it and I replaced the T-stat as it was old and her ex had taken it apart when he was trying to trouble shoot it.
Anyways it ignites and heats fine but the blower runs non-stop even after the t-stat is satisfied.
Somebody said that it could be a limit switch?
Model # on furnace is 394GAW048150

Thanks in Advance
Gary

 

[fdegree]

There are likely more knowledgeable people around here that can help more than me. But, in the mean time, I'll through out a couple of thoughts.

It could be a setting on your t'stat. If it is a programmable t'stat, check all of the different internal settings, as well as the fan setting itself, to make sure the t'stat is not calling for the fan to run continuously.

Also, there is likely a heat sensitive switch on the furnace that closes the circuit to the fan after the furnace is up to a predetermined temperature. This energizes fan, and will keep the fan running until the furnace drops below the same determined temperature, at which time this switch will de-energize the fan. If this switch is bad, it may be causing your fan to run continuously, and will likely need to be replaced.

 

[benjamin]

Fdegree has it right. Most likely the Tstat since you admit to messing with that, also the fan switch could have been bumped when you were replacing the blower motor. On older furnaces it's usually beige, 2.5x 3.5", has a cover that says honeywell and a dial with some pointers visible. If this switch also has a white button that sticks out, it will say "push on, pull auto", if you pushed it it's on so pull the white knob out.

edit: if the tstat only had two wires going to it, then it's not the tstat.

 

[Gary_602z]

Sorry it is a 2 wire t-stat as she has no AC and I can not see a reset on what I believe is the limit switch. Also read someplace that it might be a relay for the blower

Gary