There are replacement programmable heat pump thermostats from Honeywell, Hunter and others. They have wiring diagram instructions that come in the box with them, so don't throw the box and instructions away. Be ABSOLUTELY sure you read the instructions over so many times that you are ABSOLUTELY sure the thermostat can be substituted WIRE for WIRE with the old thermostat. You will have to know the model and serial number of EACH thermostat and compare their wiring terminals and terminal functions. Suppliers do not usually permit a return of controls.