The other day the weather finally cooled down from low 90's.I turned off the a/c using the thermostat, The outside heat pump continued to run. On the inside thermostat I turned it to off the furnace shut off but the outside unit continued to run, the only remedy at this time is to shut off the heat pump circuit breaker which I did at the house electric box.
What is the problem and the fix. Thanks... HarryCPD.. . Cincinnati Ohio

If you have 24 volts to compressor contactor coil, it may be the thermostat, if you don't have 24 volts at contactor coil and it is running, Contactor may be welded closed?