Carrier 59MN7B error codes

Every checked code for the Carrier 59MN7B range, with what it means and whether you can fix it yourself.

Error codes

Code	Meaning	What you can do
11	No previous fault stored	You can often fix it
13	Limit circuit lockout (depends on model)	Safe checks first, then a pro
14	Ignition lockout after repeated failed lighting attempts	Safe checks first, then a pro
15	Blower motor lockout	Call a pro
21	Gas heating lockout, fault in the gas valve circuit	Safe checks first, then a pro
22	Flame sensed while the gas valve is off	Safe checks first, then a pro
23	Flue or venting fault (depends on model)	Call a pro
24	24-volt fuse on the control has blown	Call a pro
25	Model plug missing or wrong, or a setup switch error	Call a pro
31	Flue or venting fault (depends on model)	Safe checks first, then a pro
32	Low or low-heat pressure switch did not close, or opened again	Safe checks first, then a pro
33	Limit circuit fault, a limit or rollout switch is open	Safe checks first, then a pro
34	Flame not proved during ignition	Safe checks first, then a pro
35	Modulating gas valve not communicating	Call a pro
41	Blower motor fault, speed or communication lost	Call a pro
42	Inducer motor fault	Safe checks first, then a pro
43	Lower pressure switch open while a higher one is closed	Call a pro
45	Control circuitry lockout	Call a pro
amber light off	No power to the furnace control	You can often fix it
amber light flashing rapidly	Line voltage polarity reversed or the furnace is not grounded	Call a pro
steady amber light	Normal, the control has power and no fault to show	You can often fix it