HVAC Code Lookup

Carrier Furnace Code 45.1

Soft lockoutShown as: Major code 45 on the LED (4 short, 5 long); 45.1 on the 3-digit display

Control failure - flame circuit fault, memory mismatch, or sequence error inside the control board.

Manual wording: “45.1 CONTROL FAILURE - flame circuit fault, memory mismatch or sequence error.”

Documented for: 58SC0B/58SC1B

Likely causes, most common first

  1. Internal control board failure

What you can safely check yourself

  • Turn the furnace off at the service switch for a minute and back on once - the manual says to cycle power

When to call a technician

The manual says that if code 45 repeats after a power cycle, replace the control. That is a technician job.

A Carrier furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Source

Other Carrier codes