Heat Pump Trips Circuit Breaker: I don't think my heatpump has an auxiliary heating element (yet to check) and if it does certainly we're not below freezing outside yet although it cools efficiently it's not not heating, just sitting quiet for a while and then tripping the circuit breaker.
I find the advice "reset it" pretty poor to be honest as it doesn't fix anything and no heater should ever trip your circuit breaker, this indicating a flaw in the device or its design to my mind. It should limit its maximum current demand autonomously, a circuit breaker being designed as a failsafe mechanism not something to rely on for operation. That aside, it seems to me the most likely cause is that my compressor is stalling and overdrawing current and that this is possibly, probably due to a problem with the reversing valve. It should flick when I move into heat mode (effectively reversing the roles of condenser and evaporator in the indoor and outdoor units) and if it's blocking transit of the refrigerant somehow when it tries to do this apparently this is place to look.
I intend to do this soon, and haven't yet had time, but I'm researching on-line for possible insights to support or discredit this idea and/or equip me better for on-site diagnosis this weekend. My question her then is, what would cause a heat pump to trip a circuit breaker only when switched to heat mode and after 5 or so minutes of silent inaction, in an environment that is probably between 40 and 50 degrees Fahrenheit?
I shall of course read my technical manuals at home for this model and circuit diagrams to see if ti does have an auxiliary heating coil as well, but I know from the suppliers technical support that this particular unit prevent freezing of the external condensor/evaporator pipes by dropping into cooling mode when it detects the liklihood and cycling between cooling and heating thusly (frustrating inhabitants of course ;-) to ensure that the external unit doesn't freeze. They made no mention of an auxiliary heating element.
I've in the interim diagnosed further and found the solenoid on the reversing valve (which actuates it) to be totally defunct (an open circuit, and presumably with the coils burnt out). I am soon to replace it.
A genuine puzzle remains why, if this solenoid is not activating at all, the circuit breaker trips when it switches ot heat mode (the primary result of which is to power this solenoid to actuate the reversing valve).
Dominant thinking is still a a possible compressor overload and hence overdraw on current driven by a blocked line somehow, or alternately that the solenoid itself was arcing internally when volatge was applied causing a sudden current impulse. I'll continue investigating of course as time permits.