• Replacing thermostats and transformers


    I have a heat pump which is currently set to operate as a conventional heat system and is heating with the aux/em heat only. When I put the programmable thermostat in "Heat Pump" mode, the condenser compressor comes on as it should along with the aux heat but after a few minutes of running the aux heat contactors begin to chatter. This has caused the control transformer to burn out on two occasions. I want the system to operate as efficently as possible, but can't afford to keep replacing transformers and thermostats. I am using a Hunter model 44905 programable thermostat going to a Gibson 3TB split unit and by all appearances, it is wired correctly. I recently replaced both aux heat contactors and the transformer and thermostat. Could this be an issue with the outdoor thermostat (if one exists) or has my expert service company mis-wired the unit in some way. If the OD thermostat could be the culprit, how do I determine this?

    James, Fort Oglethorpe, GA

    There are a lot of variables involved in this problem with your heat pump. The one thing that we at ARS/Rescue Rooter can tell you is not a variable is that transformers don’t just go out. There almost always has to be a short somewhere that makes this happen. This could indicate that either something is incorrectly wired, the wire itself is cut/damaged, or (less common but possible) the programmable thermostat is shorted. I would recommend having a low voltage expert come out to locate the short and get it repaired.