How To Reset Furnace After Changing Filter. Restarting is like restarting after a power outage: 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.
Check the manual to see if there’s a filter timer reset button. I pushed the reset button and it still doesn't light. After you have replaced an air filter, installed a new humidifier pad or inserted a new ultraviolet lamp, you should reset the thermostat so the display is accurate.
Set the furnace’s thermostat to the “off” position.
Turn off the thermostat, turn off the ac circuit breaker in the breaker panel, turn it back on, wait 30 minutes for the internal breaker to reset , then turn on the thermostat. The interrupted power supply clears the lockout and. A field trick he said. Sorry hvac tech did it for me once before.