My Furnace Keeps Running

If your suffering from a furnace that keeps running even after the target thermostat temperature is reached, or if it runs constantly and never reaches the target temperature, you’ll suffer with higher energy bills and less comfort.

So how do you deal with a constantly-running furnace? It starts with some troubleshooting.

Reasons Why Furnace Runs So Often:

Check the filter

The first reason you should think of when your furnace runs so often is if you haven’t  changed your furnace filter in a while, this could be the source of the problem. Over time, dust and debris clog your filter. This constricts airflow, which means the furnace has to work extra hard to maintain the desired temperature. Depending on how clogged the filter is, it may have your unit running nonstop.

Broken fan motor

When your fan motor is , broken, or otherwise faulty, it can’t operate at full capacity. That means it has to run continuously to reach the set temperature. Unusual noises from your furnace are a sign you have a broken motor.

Check the Thermostat

 Maybe someone has adjusted the thermostat to an extremely high temperature. The colder it is outside, the harder the system has to work to keep the home at such a high temperature. If the thermostat is set to a high temperature , you may want to turn it down and see if that fixes the problem.

Seal air leaks

Another reason why your furnace might not be able to reach its target temperature is that air leaks within your building envelope could be stealing warm air from your living space. Sealing windows and external doors with caulking, weather-stripping and doors weeps will help mitigate the problem.

Check the Fan Limit Switch

If the fan limit switch is pressed in, this means the fan on the furnace will run all the time. Make sure this button is switched on. This way, the fan only runs when the unit is providing heat to a home during a heating cycle.

Check your ductwork

Pushing hot and cold air through your ducts will eventually loosen duct seals and joints, causing conditioned air to escape; leaks can also develop within the duct lengths. Studies show that as much as 10 to 15 percent of the air you pay to heat (or cool) will escape through duct leaks; when that air escapes, your furnace has to make up the difference to reach your target room temperature.

When You Should Call a Professional for Your Furnace

If nothing from the problems above was facing you, it’s time to call a professional. 

Reach out to a professional as soon as you suspect a problem with your furnace—waiting can damage to your system or cause costly mid-season breakdown.