How To Reset Furnace Lockout. Check all switches and retry furnace. If your furnace has a pilot light, you may need to relight it following the manufacturer’s instructions.
The interrupted power supply clears the lockout and will. After one hour of lockout, your furnace will automatically reset itself and try to operate as usual. My furnace has been going into lockout after several retry cycles.
Most of the time a furnace will lock out because the flame sensor needs cleaning or replacing.
With your furnace’s electrical components still off, remove the panel by either lifting. Though lockout mode errors and resets do vary from manufacturer to manufacturer, most use a simple reset procedure that involves turning power off to the furnace for thirty seconds or longer and turning it back. After troubleshooting for a while, he deduced that it was probably due to a faulty circuit board, or that it could be the gas. Example = trial period is 30 seconds.flame doesnt light and trips reset.