Contractor Talk - Professional Construction and Remodeling Forum banner
1 - 14 of 14 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 · (Edited)
Hello, CT

The furnace (Tempstar) 95% rate turns on and tests fine. I just can't get it to work with the thermostat. It does not turn off or on when set automatically. The two wires (R [RH, RC Jumpered] and W) are connected. Is the wire between the two messed up somewhere in the wall? Is the wiring wrong? Help!

Appreciate all the help I can get.

Thank you
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
Thank you for your advice. I've checked the wiring on both ends and they are indeed snug...

The furnace seems to keeps cycling on and off. It heats, blows, turns off, and repeats. It does not turn off when the heat setting temperature is at the lowest.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #4 ·
The furnace stays on even though everything on the stat is set for it to be off. The only way to stop it would be to cut the power from the furnace.
 

·
Trees are Cool
Joined
·
195 Posts
I don't know much about your furnace. Isolate and mock up the thermostat and what ever other components there are. Test each one individually to see where the fault is. If you are questioning the thermostat wire, by mocking it up you can simulate the signal with jumpers.
 

·
Contractor of the Month
Joined
·
26,075 Posts
Pull off the thermostat and twist the wires together, if it behaves fine try a new thermostat.
 

·
Registered
Butcher of wood and metal
Joined
·
7,031 Posts
Sounds like a short in the stat wiring. disconnect them at the furnace , if it shuts off then you know your problem . If not well better get some one in to look at it then.


I like doing my own work as much as I can , but when do have problems know enough guys in different trades to help me out.
 

·
Registered
Joined
·
2,216 Posts
not to sound dumb. :whistling but what is a power stealing stat?
Me TOO.....TIA....


I know nothing (very little/ just laymen common sense) about furnaces and always sub that... but on my own furnace, had a similar type issue and it was just bad plastic multi-wire connector in the furnace box.

Found it by shaking the wires.... the female had been punched out of the plastic housing a little and was shorting to another thermostat wire...

I guess the original installers had forced the connector.... and it just shook with normal vibration to shorting.
 

·
Registered
Joined
·
3,920 Posts
not to sound dumb. :whistling but what is a power stealing stat?
Good question. You know about mercury stats? Bi-metal? Fast forward to the new digital electronic boards. They either require a common, or they "return" the voltage through the g circuit or w circuit. Depending on call for heat or cool.

Personally, I prefer hard-waired (connected to common). But maybe times dictate to just go with a four wire setup...

The battery takes care of programing, not switching.
 
1 - 14 of 14 Posts
Top