Performed diagnostic on carrier heat pump, upon arrival customer stated unit wasn’t heating, checked all 3 thermostats, made sure was configured correctly, checked zone board as well, all checked ok, cycled all thermostats to heat mode, unit started up, heat pump was very loud, upon inspection of air handler found suction line completely frozen all the way back to heat pump, explained unit would have to thaw completely, continued to inspect heat pump, checked wiring, also tried manually getting reversing valve to shift , only getting a click, stuck reversing valve, recommended replacing reversing valve, explained to customer they can use emergency heat to get some heat but also explained the colder it get outside the lets heat the heat strips will put out, will have to call and get part and availability, left heat pump disconnected but customer does have emergency heat at time