Troubleshooting a High Efficiency Heat Exchanger Furnace

Turn the main power switch on the furnace to “On” if the furnace is not operating. Make sure the gas valve is turned on in a counterclockwise motion but stop immediately if you smell gas. Turn the furnace back to “Off” and leave the home. Call your gas company for help.

Set the house thermostat to “Heat” if the furnace has power and gas but is not operating and adjust the temperature to a warmer setting that is approximately 5 to 10 degrees warmer than the ambient temperature.

Open the access panel and use a flashlight to view the heat exchanger inside the furnace up near the top. Contact the furnace manufacturer or another service professional if you see signs of rust, soot, corrosion or leaks of any kind.

Locate the air grilles and vents throughout the home if the home does not seem to be heating as expected when the furnace is running. Move objects, like rugs or furniture, away from the vents and make sure the vents are in the open position.

Turn off the furnace and open the control access panel to get to the filter if the heating is inaccurate or the furnace is noisy. Release the clips holding the filter in place and take the filter out of the furnace. Clean with soapy water and rinse well if the filter is permanent. Replace with a new filter if disposable. Dry the filter if washed before replacing in the furnace and secure the clips. Remember to close the access panel before restoring power.

Perform a reset if the furnace shuts off due to a power failure. Move the thermostat to the lowest setting and turn off the furnace, and then open the burner access panel. Turn the gas control switch to “Off” and wait five minutes. Stop if you smell gas after five minutes and leave the house to call your gas company. Turn the gas control to “On” if there is no gas smell, close the access door and restore power to the furnace. Set the thermostat to the desired temperature.