DIY Furnace Repair/ Pilot

Repair furnace ignition switch or pilot light

Older gas and combustion-fuel furnaces have pilot lights; some newer ones have electronic ignition. If your older furnace has a pilot light that won’t stay lit, the thermocouple may be loose or faulty, the pilot orifice may be clogged, or the pilot’s flame may be set too low. pilot light flame

You can clear a clogged orifice with a piece of thin wire. Be sure to turn off the gas to the furnace first. Also shut off the switch or circuit breaker that controls power to the furnace. Just poke the thin wire into the tiny orifice where the pilot flame normally burns to knock out any debris.

Some pilot lights have a flame adjustment screw. Refer to your owner’s manual, but normally this is simply a matter of turning the flame adjustment screw to achieve a full, steady 1 1/2-inch to 2-inch flame with no yellow in it.

Your gas- or oil-burning furnace must receive fuel to work. With a gas-fired furnace, be sure the valve on the gas pipe is turned on (the lug or handle should be in line with the gas pipe). With an oil furnace, check the fuel supply.

On an electronic-ignition furnace, turn down the thermostat or turn the power switch off and then on again to reset the ignition control module. Listen for the sound of the spark or watch for the hot surface ignitor to glow (see your owner’s manual).

If your furnace has a pilot light, be sure the pilot is lit. Check your owner’s manual or the instructions posted inside the furnace cabinet for step-by-step lighting instructions. Usually this involves turning the gas valve to Off, waiting a couple of minutes, turning it to Pilot, pressing and holding it down while you light the flame, and waiting a minute or so, releasing it, and then turning it to On.

If the furnace won’t light or ignites but fails again, call a furnace repair technician at Air Done Right.