Why Won’t My Heater Stop Running?

Continually Running Heater?

Winter is coming to Phoenix, and while we don’t see the extreme cold weather that our northern neighbors experience, it’s still critical to have a working heater for those chilly Arizona nights. So, what does it mean when your heater won’t turn off? Here are a few causes of continually running heaters and what to do about them.

Which Part of the Heater is Running?

The first step to deciphering an issue with a constantly-running heater is isolating which part of the heater is running. Is the furnace blowing air continually, whether the air is warm or not? Or do the furnace burners remain on no matter what you try?

 

Furnace Blower Won’t Turn Off

If it seems that air is constantly pushed through the vents, whether it’s hot or cold, there may be an issue with the furnace blower. There are a few common causes of this problem:

Thermostat Fan is On

The most common cause of a continually-running heater is the setting of the thermostat. Make sure that the thermostat fan setting isn’t set to “ON.” Switch it to “AUTO” and see if that causes the thermostat to turn off.

Problem With the Thermostat or Fan Relay Switch

Another common cause of a continually-running heater is an issue with the fan relay switch. Turn the fan setting to “OFF” and see if that turns off the fan. If it does not, the thermostat or fan relay switch is faulty. Call a professional heating repair company to diagnose and fix the issue.

Pilot Light is Out

If no heat at all is coming from the vents, but the heater is continually blowing, the pilot light may be out. Relight the pilot light or hire a professional to come to diagnose the issue.

 

Furnace Burners Won’t Turn Off

If the heater continually blows hot air, the furnace burners aren’t turning off. Here are a few reasons why:

Thermostat Set Too High

Ensure that the thermostat isn’t set to too high of a temperature. In these cases, the heater will struggle to keep up on a cold night and will continually blow hot air.

Dirty Air Filter

Another common cause of a constantly-running heater is a dirty air filter. When air filters get clogged, air can’t pass it to enter the home. In these cases, the heater will constantly run because the air in the home can’t reach the thermostat’s setting. Check the air filter and change it if it’s clogged or dirty. Most air filters need replacing every one to three months, more often if there are pets or people with allergies in the home.

 

How To Turn the Heat Off

If you need to turn the heat off because of a constantly-running heater, and a licensed professional isn’t available to come to diagnose the problem right away, try the following and see if it helps:

Adjust the Thermostat

For thermostats without an off switch, try adjusting the temperature to below the current room temperature. If the thermostat is properly adjusted and works well, this should turn the heat off. For thermostats with an off switch or a cool switch, try turning the thermostat to off or cool. This action should turn the heater off. If not, a professional technician needs to diagnose the problem as soon as possible.

Cut the Power

If all else fails, homeowners may need to cut the power to the heater for it to turn off. Powering down the entire heating system is a surefire way to turn the heater off. Some systems have an on/off switch near the furnace, usually red and labeled.

 

What Else Can Cause the Heater to Stay On?

The thermostat and the fan relay switch are the two most common causes of a constantly-running heater. However, the culprit could also be one of the following:

Damaged Primary Controller

If the thermostat is not the problem, the primary controller on the heating unit may be defective. Certain mechanical and physical issues may affect the primary controller and cause the heat to run all day. Have a professional heating and air technician come to properly diagnose the issue if you suspect the primary controller is the cause of your heating problems.

Defective Check Valve

If the heater system in the home relies on hot water, the check valve is vulnerable to damage. If the check valve is faulty, water circulates on its own. This circulation keeps the heater running. A licensed professional can replace the valve and investigate the water-checking system if this is the issue.

 

What To Do if the Heater Won’t Turn Off

If adjusting the thermostat doesn’t work and no other investigative measures prove fruitful, homeowners should power down the heater and call a licensed professional to diagnose the issue. A working heating system is vital for the family’s comfort this winter, so don’t delay.

 

How Can Day and Night Air in Phoenix Help?

If the heater in your home won’t stop running, you’ll need heater repair services. Day and Night Air in Phoenix, Arizona has a qualified staff of licensed professionals ready to help when you need it.

 

Free Estimates for Heating and Cooling Repair

From heater repair and maintenance to new heater installations and replacements, Day and Night Air is a full-service heating and cooling company dedicated to customer satisfaction. Don’t spend any more time in discomfort, contact us today for a free estimate from one of our heating and cooling experts!