Why the Furnace Constantly Turns Off and On

A dirty filter can prevent airflow through the furnace’s system, making it work harder.

There can be many different reasons why a furnace turns off and on. A homeowner must determine the cause and repair the problem ao the system doesn’t have to work harder than necessary to warm a home. Even minor problems can strain a furnace and cause it to work harder, leading to higher energy bills and a shorter overall lifespan for the system.

Professionals can inspect a furnace to establish the problem and take steps to repair the system to return it to good working condition.

Following are some reasons Furnaces turn off and on continuously.

Dirty filters

A dirty filter can prevent airflow through the furnace’s system, making it work harder. The system will turn off and on repeatedly to prevent overheating while trying to regulate the space’s temperature. Regularly changing the filter is an inexpensive way to prevent this problem.

High limit switch

All furnaces have a high-limit switch, a safety feature designed to prevent a furnace from overheating. If the furnace does overheat, the high-limit switch is activated and shuts the furnace off. An HVAC professional can determine why the system is overheating and make suggested repairs.

Flame sensor

A flame sensor gauges how much gas is going into the furnace. It is another safety feature that helps furnaces perform their best. If the sensor is dirty, it won’t be able to do its job correctly. Because it can’t tell how much gas is entering the system, it will prevent gas from flowing through the furnace to avoid excessive, dangerous gas buildup.

The furnace blower

A furnace can run even if the blower is not working correctly. However, if the motor is not working properly, heat will build up inside the furnace instead of being blown over the heat exchanger. This buildup will also cause problems with safety features. An HVAC specialist can determine the cause of a faulty blower motor and make necessary repairs.

If a furnace turns on and off repeatedly, contact a licensed HVAC technician for help, as this issue can cause additional wear and tear on the system and be a safety hazard.

Forecast Heating, Cooling, and Refrigeration serves residential and commercial customers in Summerlin, Anthem, North Las Vegas, Boulder City and Las Vegas. Call us at 702-919-4546.