Please help diagnoses: thermostat or system issue?
I have a gas pack/heat pump that is controlled by a Honeywell
TH8320U1008 thermostat. We are in a new building and everything was working well with Summer and AC but now that we need heat we have a problem.
The thermostat will be set on 69 degrees but when we arrive in the morning it is 64 degrees inside. If I pull the thermostat off the wall and replace it on the mount the system immediately kicks on and heats. I have replaced the batteries in the thermostat and the display appears normal.
What can cause this and what do I need to do to remedy the situation.