If the circuit board is bad, would the furnace work at all? My furnace works fine sometimes, but a couple times a day, usually in the middle of the night, it blows out cold air only. Two techs have told me circuit board is fine, but the 3rd tech said circuit board is bad. Please Help!!


A board can cause weird things since it's in control. When it goes the furnaces can work intermittently. I'm not diagnosing your problem, however. Just answering your question that yes, a bad board may still allow the furnace to run intermittently.

Updated on January 22, 2018

Original Article:

Troubleshooting Common Furnace Problems With an HVAC Expert
By Dan Robbins