It’s easy to do if you have an electrical multimeter ($28 and up at home stores, hardware stores and online). If the 3 steps above (thermostat, motor on, motor off) happen, it is reasonable to suspect and inspect the ignitor. Troubleshooting a Bad Igniter, Part 2: Inspecting the Igniter If all that happens and then your furnace quits before heating your home, it’s definitely not the ignitor. The gas hits the hot surface ignitor, and whoosh, your furnace is firing up. The gas valve opens, and gas flows into the burner ports. What happens in a working furnace is that once a draft vacuum is established, the ignitor (aka hot surface ignitor or furnace glow plug) is energized. Inducer Motor part 2: The draft motor will run for a few minutes and then shut off without the furnace firing. If the vent is blocked, no vacuum can be created, and the pressure switch will signal that, and the furnace will turn off the draft inducer motor.ģ. Your chimney vent: Only do this if you can safely get onto the roof to check to see if the vent is blocked by snow/ice, a bird’s nest or the nest of a squirrel or similar critter looking for a cozy place to spend the winter.Is it possible someone turned it off? An inquisitive child? Someone changing the filter (not necessary to turn it off to replace a filter, but some folks are the cautious type)? If the furnace starts but trips the breaker again, there’s an electrical problem, which should be diagnosed by a furnace technician. Turn it all the way off and then back on to reset it. If it’s tripped, it will be in sort of a middle position, not on or off. It should be labeled on your electrical panel. An HVAC technician is probably needed to diagnose it.īefore you call for furnace repair, check three things: Control board (expensive) or other electrical issue.Pressure switch designed to sense that a vacuum has been created for safe venting (cheap to moderate).Inducer motor, aka a draft inducer motor (moderate to expensive).

If nothing happens, you might have a bad:

This creates a vacuum, so that harmful exhaust fumes containing carbon monoxide are properly vented. It’s purpose is to get airflow moving through the combustion chamber and out the chimney. Inducer Motor: You should hear a motor start in the furnace called the inducer motor. If it’s 65F in the house, for example, set the thermostat to 70F.Ģ. Thermostat: Make sure the thermostat setting is above the home’s temperature. Here are the steps to diagnosing a bad furnace ignitor (sometimes spelled igniter, so we use both. It starts with no heat, of course, which can be a shock on a cold February morning. How to Tell if Your Furnace Ignitor is Bad If your furnace ignitor goes bad, that’s good – at least in the sense that if your furnace is going to break down, this is a cheap and easy repair you can do yourself if so inclined.

Clare Furnace Serial Number