What Happens When Your Heater Won’t Actually Heat

Monday, January 4th, 2021

woman-wrapped-in-blanket-drinking-out-of-mugWhether you have an electric or gas furnace, you count on it for powerful performance right? Well, as long as you properly take care of your heater, you’ll never have to worry about it failing on you. But no heater is immune to problems, no matter how well maintained.

So what if yours is running, but it doesn’t seem to be actually heating your home? Maybe you’ve tried raising the thermostat to make up the difference to no avail.

This means your furnace or heating system is malfunctioning in some way, but what could be to blame? 

The Thermostat Was Set Incorrectly

Sometimes it’s not that your heater has a problem but instead an issue with the controls—that is, your thermostat. In the age of Wi-Fi and smart thermostats, it’s easy to accidentally alter the settings on the thermostat.

Check the programming on your thermostat to make sure that it’s not only turning the furnace on and off at the right time, but it’s at the right temperature setting and that it’s set to heat and not fan only.

It’s also possible that the thermostat was miscalibrated. When this happens, the temperature sensor inside the thermostat can start picking up readings that are a few degrees off. For instance, let’s say you set your thermostat to 68°F but your thermostat thinks it already is 68°F even though it’s really 64°F. It’s not going to cycle on enough to keep your home warm enough.

Clogged Air Filter

This is, fortunately, a problem that’s easily resolvable. Many folks think that the furnace air filter is in place to protect their indoor air quality, but it’s actually in place to prevent dirt, dust, and other debris from infiltrating the interior components of the heating system itself.

If that air filter gets too clogged up, it can restrict airflow and make it harder for your heater to function as it should. Homeowners should be changing this filter out every 1-3 months during periods of use—this includes changing your air conditioner’s air filter as well.

Air Duct Leakage

Again, the problem with your heater might not be a problem with your heater itself but rather with a component connected to the system—in this case, your air ducts. Damage along the ductwork allows heated air to escape into unoccupied spaces, such as your attic, crawlspace, or within the walls.

This isn’t something that you can fix on your own. Folks sometimes think that duct tape is the answer, but it actually isn’t appropriately named—it won’t work on your ductwork at all. Fortunately, we can help! Contact our team to locate the damage and repair it as needed.


When a furnace or heating system shuts off before it completes a full heating cycle, only to turn back on again soon after that, it’s called short-cycling. This wastes energy since your HVAC systems use most of their energy cycling on and off. It also puts excess strain on your heater.

Whether it’s a problem you can fix on your own, like a thermostat that wasn’t set correctly, or you need professional assistance, you can give us a call! We’re happy to answer any questions you have about your heater’s performance.

Contact Comfort First Heating and Cooling, Inc. for professional heating repair in New Lenox, IL!

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