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 Rick Your Own Question
Rick, HVAC Supervisor
Category: HVAC
Satisfied Customers: 20364
Experience:  40+ yrs. experience as a licensed oil & gas technician.
Type Your HVAC Question Here...
Rick is online now
A new question is answered every 9 seconds

Furnace lockout on GCVA070BX40. LED is one blink.

Customer Question

Furnace lockout on GCVA070BX40. LED is one blink.
Submitted: 3 months ago.
Category: HVAC
Expert:  Rick replied 3 months ago.

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. First I’ll need some more info so I have a more complete picture of you situation.

1 flash is ignition failure. Does the igniter glow? do the burners fire up then go out?

Customer: replied 3 months ago.
The schematic label says that 1 flash is a "System lockout (retries/recycles exceeded). 8 Flashes is "Check ignitor or improper grounding). The ignitor does glow every time. The main burner never turns on.Previously, I was getting 2 flashes = Low fire pressure switch stuck closed. I changed the inducer blower and no longer get this code.
Expert:  Rick replied 3 months ago.

Ok, you need to check for 24 vac at the gas valve while the igniter is glowing. If you have 24 v at the valve leads and the burners don't fire up then you have a faulty gas valve. If you don't have 24 v then you either have a bad board or a bad connection between the board and the gas valve. I'm assuming you have adequate gas pressure at the gas valve inlet.

Customer: replied 3 months ago.
OK, I can check that around noon today.
Expert:  Rick replied 3 months ago.


Customer: replied 3 months ago.
Furnace runs now. I wonder if the control was in a hard lockout due to the number of lockouts incurred. I had the power shut off to the furnace all night long. What is the procedure to reset a hard lock out on this furnace? This is different than a soft lockout after three failed lighted attempts. If it runs now, what should I look at for preventive maintenance moving forward?
Expert:  Rick replied 3 months ago.

Cycle the power off, wait a couple minutes then cycle it back on to try and clear a hard lockout. This will only works with a few errors but a 1 error is one that should work. With a soft lockout the unit will retry on its own after a period of time usually 1 hour. One thing you can do for PM is to clean the flame sensor rod with steel wool. Also change the filters every couple months depending on how dirty they get

Related HVAC Questions