When a furnace doesn’t produce heat or stops working altogether this time of year, it’s stressful. Before you call in your HVAC pro, you can use the following tips to troubleshoot your furnace and identify whether there’s a simple problem you can fix yourself.
- Set the thermostat on “fan” mode. If the fan doesn’t come on, check for a tripped breaker, a blown fuse, or whether the furnace was accidentally switched off. If you reset the breaker and it trips again, there may be loose wiring inside the furnace.
- If you have a condensing furnace, check whether the reservoir is full. When it’s full, the float switch inside trips and shuts the furnace down. Emptying the reservoir and resetting the switch should solve this issue.
- If your older furnace has a pilot light, make sure it’s lit. Check that the flame reaches the thermocouple tip. If it doesn’t, it may need to be adjusted.
- If the pilot light or the burners won’t stay lit, the flame sensor rod may have a build-up of carbon. Try cleaning it with steel wool or fine sand paper.
- If your pilot light is working properly, but the furnace is cold, the burners aren’t igniting, so check that your gas supply is turned on. If it’s already on, there may be a problem with the gas valve.
- On furnaces with spark ignition, you should hear a clicking noise that indicates that the furnace or burners are trying to ignite. If you don’t, check whether the flue is blocked. If it’s clear, a faulty control board could be the culprit.
- When the burners won’t stay lit on your condensing furnace, the drain line might be clogged with sediment, and cleaning out the trap could solve the problem.
- If the burners stay lit, but your blower doesn’t cycle on, your HVAC professional may need to check its motor and run capacitor.
If you need expert advice to help troubleshoot your furnace issues, contact us at Aggressive Mechanical Contractors, Inc. We’ve been serving the home comfort needs of Monmouth County and the surrounding areas for over 60 years.
Our goal is to help educate our customers in Monmouth County, New Jersey and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about troubleshooting furnace problems and other HVAC topics, download our free Home Comfort Resource guide.