I will be going on a service call in the morning to check an Amana thru the wall heat pump model # PTH153A50AC with remote control that Im told has a history of control boards being replaced among other things such as transformer, capacitor, and even the compressor over the past 3 years. Needless to say the customer is not happy but this time he says the unit will come on for roughly 30 seconds and shut off for about 5 minutes or so and basically do this over and over. Any input would be very helpful, Bad thermistor sensing temp maybe? or bad board again?