Ruud UBHC Air Conditioner "t874r1434" Questions

No power to thermostat I have a RUUD T874R1434 Thermostat Model # UHQA-1015TKS that I need help with wiring. Before I can help you I need you to make a list of what you have and answer these questions

I have t874r1434 thermostat. when I turn it on the heat pump model UPLA-030JAZdoes not quick. but the inside unit does. Sometimes it will work. WHY this problem, Sometimes the contactor get welded ...

Want to replace a T874R1434 thermostat with aux heat with a visionpro th8000. Have a blue wire connected to the B terminal on old thermostat and what looks like a brown wire connected to the X ...

...with manual thermostat. Inside unit is UBHC-17J11SHG, outside unit is UPMC-030JAZ, thermostat is T874R1434. New thermostat is Honeywell Vision Pro 8000 series (TH8320U1008). When I remove the ...