I'm having an intermittent problem with my 7 year old Rheem electric
(forced air) furnace. About 2-3 random times a week the furnace will
fail to turn on despite the room temperature being below the
thermostat set value. To get it to function normally, I turn the
furnace off (at the thermostat), wait a few seconds, and turn it back
on. The furnace will then return to normal function from anywhere
from 12 to 72 hours, then it'll happen again.
Other interesting notes. When the furnace is 'malfunctioning' I have
seen the heating coils on, but not the fan (this obviously should
never happen). My immediate thought was that the blower motor was
going bad. The problem with this theory is that the blower always
comes on when I turn the fan on at the thermostat. So it appears to
me that the thermostat is either not sending the command to turn the
blower on (but is telling it to turn the heating elements) or that the
furnace is unable to always get the motor going. The thermostat is
digital (White-Rodgers) so it seems unlikely that it would work
Oh and I did replace the motor start capacitor because it was cheap
and easy. It didn't help.
I am stumped. Anyone have a clue here?