How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask BillyHvac Your Own Question
BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22629
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
Type Your HVAC Question Here...
BillyHvac is online now
A new question is answered every 9 seconds

Having problems with my 58STA/STX model Carrier furnace. The

This answer was rated:

Having problems with my 58STA/STX model Carrier furnace. The thermostat screen started going blank on and off for this past week. Lasts only a few moments, then comes back on with "HC" on the screen for a second and then back to the normal temperature reading.

Today, it appears to be running intermittently, turns off, then back on despite temperature not reaching "goal". Still pumping out heat, fan seems to be working.

Interestingly the thermostat issues do not seem to coincide with the furnace issues. Is this just a thermostat problem?


This is normally a case of the furnace overheating...shutting burner off (and thermostat power) cools...and everything magically comes back on. This can be as simple as a dirty filter....or in the case of a Carrier, a bad circuit board turning power ogg to blower. Check filter first...then see if when stat is blank if blower is still running or not.



Customer: replied 6 years ago.
Filter should be fine. I assume I need someone to come check the furnace for the circuit board issue?

I do think the stat goes blank when the furnace "sound" changes, though the blower seems to be running. Sounds like a circuit board issue?


I am just going by the make/model...the fact they had numerous issues with the blower function from circuit board, and your symptoms.


It is a very common occurence with that unit...but without a meter to test I am going by experience.



BillyHvac and 2 other HVAC Specialists are ready to help you