Just had new Coleman oil fired (with AC add-on) installed with Honeywell PRO TH3000 nonprogrammable thermostat. Mobile home. AC portion of unit HAS NOT been installed yet.

Turned thermostat on and set to 75 degrees. Heater comes on, sounds normal, but will not stop running when temp is above 75. In order to stop heater, you must turn off switch on thermostat. Have tried this multiple times and end result is same, temp in house exceeds 80 and does not stop until switched off.

My 80-year-old mom hired (literally) the guy next door to do this work. He now says it's "bad thermostat" or "wired wrong" or "I don't know" and mom is essentially afraid to use the heater. Any thoughts or help would be appreciated before this turns into a major situation for my mom. Thank you!

 

Just make sure the wires are done right.

T-stat-----Fur
R/Rc-------R
G-----------G
Y-----------Y
W1---------W
C-----------C If have this wire.

make sure switch on back of t-stat is set to Gas/Oil

Setup Menu-

1-0
2-3
9-2
14-o
15-5


If still does it again after checking above, it may be a bad t-stat.

Make sure W wire is not jumping or shorting out.

What happen if you turn the temp down low, and put the switch to HEAT?

 

Thank you so much. Last time it came on, we had serious problem with fumes, so before turning on again, going to have this checked. We are going to verify against your instructions here and see if all is wired correctly as well. Will leave followup when we get this figured out. Again, thank you!

 

Sounds good.. Keep me posted on your results.