Heat pump doesn't shut off

jdmitche

I've recently noticed that my thermostat will say that the inside temperature is at the desired temp but the heat pump will still be running unless I cut off the unit at the thermostat. When I start it back up, everthing works fine including the air handler but when it gets back up to temp, the air handler cuts off as it should but the heat pump does not.

Done That

Y (compressor) output relay in thermostat could be sticking, since the blower is a seperate G (fan) output relay and it seems to be behaving.

Outdoor unit either has to have a 24V Y output coming to it telling it to run, or a stuck contactor that is keeping the unit running without Y present.

Marty S.

If it doesn't go above the thermostat setting don't worry about it. Thermostats display whole numbers but read in tenths so set on 72 and room 72 display could mean it has another 9/10th of a degree to heat up before the thermostat satisfies.