Posted: February 24, 2020

What Should I Do If My Furnace Won’t Stop Running?

Your furnace works hard to keep you warm all winter long – but sometimes it can work a little too hard.

If you’ve noticed that your furnace keeps running even after it reaches the temperature on your thermostat – or if it keeps running but never reach the target temperature – you’ll end up with higher heating bills and a less comfortable home, and you might even wear out your furnace prematurely.

So what should you do if your furnace is running nonstop? Start with a little investigating.

When your furnace keeps running but never reaches your desired temperature:

• Check your thermostat – Make sure your thermostat is set to a reasonable temperature (the U.S. Department of Energy recommends 68°F in winter for the best balance of comfort and efficiency). If it’s set too high, your furnace could run for a long time without ever reaching your thermostat temperature, especially on a cold day.
• Change your furnace air filter – A dirty or clogged furnace air filter will reduce airflow in your heating system and prevent warm air from reaching your living space. Check your filter once a month during winter, changing it as needed.
• Check for duct leaks – Seals, joints, and even straight sections of ductwork will eventually leak, causing warm air to escape; if 10 to 15 percent of the warm air produced by your furnace doesn’t reach your living space, the furnace will have to make up the difference. Seal visible ductwork leaks and consider having your ducts evaluated and sealed by professionals every three to five years.
• Weatherize your home – One reason why your furnace may be laboring is because your home is fighting against it. Leaks around windows, doors, and within walls and ceilings can rob your home of 15 percent or more of its conditioned air. Adding insulation, sealing windows with plastic, installing doorsweeps on exterior doors and replacing old caulking and weatherstripping will all help in the fight against air leaks and drafts.

When your furnace continues to run after the temperature has been reached:

• Check the blower motor – If you have a furnace, you have a forced air system with vents. To get air from the furnace to the vents, your heating system uses a blower, which pushes heated air through your ductwork. That blower can be operating whether or not the furnace is actually producing hot air, which is exactly what will eventually happen if you set your thermostat’s heat mode to “on.” When you set it to “auto”, on the other hand, the blower only runs in tandem with the furnace…meaning that both the furnace and the blower will shut off when the target temperature is reached.

  If your furnace is constantly running, check the settings on your thermostat; if it is set to “on,” switch to “auto” and see if the problem goes away.

• Troubleshoot your thermostat – If switching from on to auto didn’t fix the problem, check your thermostat for things like disconnected or frayed wires or obvious problems like worn batteries. If you change the batteries doesn’t fix the problem, you’ll probably have to install a new thermostat.

If none of these solutions fixes your problem heating system, contact a heating professional at Sail Energy for service. Our expert heating oil technicians and propane technicians will diagnose the problem and fix it quickly so you can get back to enjoying cozy, comfortable nights in your central Maine home.

For expert heating oil and propane furnace repairs in Androscoggin County, ME, trust the pros at Sail Energy. Contact us today to learn more.