Customer states system was not keeping up this morning and failed to recover from nightly set back. Checked operation of heat pump and furnace. Both systems operate normally. Took a look at thermostat faults and furnace fault history and did not note any faults over the past month. Believe system thermostat wasn't allowing furnace heat to come on due to lock out settings. Adjusted lock out temperatures and adjusted heating droop to help system run more consistently. Performed heating tune up service on dual fuel system checking all electrical components, refrigerant balance, unit start up, operation, defrost, shutdown, cleaning of furnace components, performance of full combustion analysis. Everything looks and runs great!