A few furnace troubleshooting procedures can be a lot of help when you need the services of an HVAC professional to address a problem. Most of what might go wrong with a modern furnace is beyond the capabilities of the typical homeowner to repair. For safety reasons, you shouldn’t even try. However, the process of getting professional service can often be expedited if you can communicate a few things about the problem to the HVAC technician who makes the service call. Here’s a sample of the troubleshooting flow chart for some common furnace problems:
Furnace fails to light
The electronic igniters in modern furnaces are generally more trouble-free than old pilot lights. If the furnace doesn’t ignite, listen for the whooshing sound of the draft inducer circulating air. If you hear the inducer but don’t see the burner light, you’ve probably got a bad igniter. Take a look at the igniter — but don’t touch — for cracks. Note whether it glows red when the draft inducer runs. Let the technician know what you saw.
Draft inducer doesn’t operate
If you can’t hear the whooshing sound of the draft inducer when the thermostat signals the furnace to ignite, a bad control board may be at fault. Another possible cause might be a circuit breaker that controls electricity to the furnace. Furnaces incorporate limit switches to prevent unsafe operation under certain circumstances such as high temperatures. A defective limit switch may also be responsible for an inoperative draft inducer.
Burner goes out
If the burner flame goes out soon after it ignites, a safety switch in the condensate reservoir may be turning off the gas supply because the drain is plugged, and overflow may be imminent. Flame or heat sensors may also become coated with residue and no longer sense heat accurately. If insufficient air for combustion is available — due to clogged air intakes or furnace filter — the system may shut itself down as well.
For quality heating, cooling, plumbing and electrical services, Comfort Services is your one-call source in the Wichita area. Contact us to handle all your maintenance and furnace troubleshooting issues before the first cold snap hits.
Our goal is to help educate our customers in Wichita, Kansas about energy and home comfort issues (specific to HVAC systems). For more information about furnace troubleshooting tips and other HVAC topics, download our free Home Comfort Resource guide