Model RRPBL030JK06X, 14 seer, 80% AFUE, R410A, Natural Gas Heat, Electric Cool. Professional installation 8/2006.
Current overnight temps 48F, daytime temps 78F. Set thermostat for 69 to come on at 4am (Heat + Auto Fan). I wake up at 6am to find the house is 62 and the heater is not running. I switch the unit to off then back to Heat and:
Relay on thermostat clicks
Unit on roof hums
Fan does not start
If I flip the fan from AUTO to ON, it blows cold air. Then flip it back to AUTO and it never starts back up, just hums. Finally at 10:30a it started up and began to blow warm air.
This is intermittent. It can work fine for days, then one day just won't run right. Sometimes I notice the unit will hum for like 15 or 20 minutes or longer before it starts up. Usually it only hums for like 3 to 5 minutes.
I want to get the installer out to inspect it, but if it won't malfunction when he is here what can be done?