Why Does My Heater Keep Running?

Why Does My Heater Keep Running?


It seemed like spring was here until this sudden blast of chilly air came through to keep things cool for another week! With temperatures in the 40s for at least the next couple of days, it’s likely that you’ll want to turn on the heater to keep the chill away.

A frequent question we receive here at Brown Heating and Cooling during colder times of the year is, “Why does my heater keep running?” This is a very common problem, and it usually has an easy fix. Most homeowners can do a little sleuthing on their own and correct the issue in no time.


Check Your Thermostat

The very first thing you should do if your heat is continuously running is head to your thermostat for a troubleshooting session. It may seem like the simplest thing in the world, but your first check should be the heat setting. Check to make sure that your system is set to “heat,” and that the temperature is set to a reasonable level. If the temperature setting is too high, chances are the problem is that the system can’t meet the demand for that heat setting.

One of the most common causes for a heater that will not shut off is the fan setting. If your heater is on, the next check is the fan switch. Sometimes this switch is accidentally changed from “auto” to “on,” which will cause the fan to run indefinitely, making it seem like the heater is never turning off.

If your heat is on and the fan setting is “auto,” confirm that the temperature in the room is lower than the setting on the thermostat. If this is the case, move on to the next troubleshooting tasks. If the temperature is higher than the thermostat setting, it’s time to call a professional.


Check Your Air Filter

We cannot emphasize this enough – check your air filter on a monthly basis! A dirty filter can cause all sorts of problems, up to and including a heater that won’t turn off.

Why does this happen? Dirty filters cause airflow restriction through your HVAC system. This reduction of airflow means that your system has to work harder in an attempt to warm your home. For filters that are filthy, the heater may never be able to reach the set temperature on your thermostat. Instead, it will just keep running, eating away at your energy bill until the problem is solved.


If You Have a Furnace, Check the Pilot Light

For those using a furnace to supply heat to their homes, another possible issue could be the pilot light. The pilot light is the flame source to ignite the fuel burned to produce heat – if it goes out, you are left with an HVAC system that is blowing cold air in the wintertime.

There are a few reasons why a pilot light could go out. Over time, grime and soot can clog the nozzle, making it hard for fuel to supply the flame. Another reason for a flame that is completely out is a lack of fuel. If the flame is out, you can try to reignite it using the directions from your owner’s manual. If that doesn’t work, it might be time to call a pro.

There is also the possibility of having a flame that is just too small to ignite the furnace burner – in this case, your owner’s manual should provide information on how to adjust the flame for your particular heater.


Check for Leaks

If your thermostat and filter seem to be in good working order, your next check should be for leaks in your ductwork. Over time, the ductwork in your home can wear down, especially at places where ducts connect. Doing a thorough check of your ducts, including those in the attic, can reveal small holes or other failures that allow air to escape. If leaks are bad enough, the air escaping can reduce the overall efficiency of your heating system, causing it to run continuously.

Remember – duct tape is not a good solution for fixing leaks! Instead, head to a local hardware store to find aluminum sealing tape.


Check Your Thermostat, Again

If you have reached this point and are still having trouble, take a quick trip back to the thermostat. Gently remove the outer casing and look at the wires. Does everything look like it is connected correctly? Sometimes a loose wire can cause a connection problem, throwing off your HVAC system.


Nothing working? It sounds like it’s time to give us a call at (205) 871-8111 to schedule an appointment!