Coleman EB17B THERM OFF BUT HEAT ELEMENTS ON ALWAYS

[gamorrow]

Just started last night-- woke this morning to a cold home...went to the furnace and it was warm standing by the unit...opened unit...hot around heating elements and sheet metal, but no running fan.

Went to the thermostat and rocked the control arm up-and-down several times listening to the clicks...waited a minute then the fan turned on.

After the house warmed up...unit automatically shut off...but the heating elements were still on.

The unit now autos on-and-off and the fan runs but the heating elements remain on...but this might be until today while all is asleep.

Any ideas???

[gamorrow]

Just found the problem...I looked over the Lower Control Board 7681-317P, and I spotted a loose resistor joint where the solder meets the resistor lead. Resoldered the loose joint and the unit is working fine again.

[Robert]

The blend air system is wired/spliced into the low voltage wiring, but is not part of the furnace system.


Depending on wiring, it could possibly cause a problem if a short were created.


Thanks,
Robert