If your heater won’t turn off, the first thing you do is check the thermostat. The thermostat controls how the heating system runs. It detects the indoor temperature and signals the furnace to start or stop. So, if the thermostat malfunctions, it can signal the unit to run continuously.

Why does my heater keep running after it has reached the set temperature?

When your furnace keeps running after the temperature has been reached: Check the blower motor – Your forced air heating system uses a blower to push air through ducts and into your living space; sometimes, the blower runs at the same time that your furnace is heating the air, but sometimes it runs on its own.

What would cause a furnace to not shut off?





If your furnace won’t shut off, you likely have one of the following issues: Thermostat issue. Dirty air filter. Faulty blower.

Why won’t my heat stop running?

A faulty thermostat can cause your heating unit to run and not turn off. The unit may have a broken heating sensor, the wiring may have gone bad, or the switch itself may have broken. The older the thermostat is, the more at risk you are for this happening. Fortunately, a broken thermostat is an extremely easy fix.

How do you fix a thermostat that won’t turn off?

Thermostat Troubleshooting: heating or cooling system won’t turn OFF

  1. THERMOSTAT WON’T TURN OFF – page top.
  2. STEP 1: CHANGE THE THERMOSTAT SETTING.
  3. STEP 2: CONFIRM PROBLEM in THERMOSTAT or WIRES.
  4. STEP 3: CHECK DAMAGED THERMOSTAT WIRES.
  5. STEP 4: IF THE PROBLEM is NOT THE THERMOSTAT.
  6. EXAMPLES of THERMOSTAT TROUBLESHOOTING.

How long should furnace run after reaching temperature?

With all that being said, if there are no extreme factors involved, the average run time for a furnace is 10-15 minutes per cycle. Your furnace may need to run two to three times an hour to maintain your desired temperature if your home has average insulation.

Why is my heat continuously running?





Inspect Your Air Filter
A clogged, dirty air filter can cause your heating system to work overtime. It’s not able to send enough heat into your home, so it just keeps running. The air filter should be cleaned and replaced every two to three months.

How do I know if my thermostat is bad?

7 Ways to Tell Your Thermostat Is Broken

  1. Thermostat Has No Power. …
  2. AC or Furnace Won’t Turn On. …
  3. Heater or AC Won’t Turn Off. …
  4. Thermostat Doesn’t Match Room Temperature. …
  5. Thermostat Doesn’t Respond. …
  6. Short Cycling. …
  7. Thermostat Forgets Programmed Settings. …
  8. Thermostat Replacement Services.

How do you know if your home thermostat needs to be replaced?

7 Signs You Need to Replace Your Thermostat

  1. Your HVAC Keeps Turning On or Off. …
  2. Faulty Thermostat Readings. …
  3. Suspiciously High Energy Bills. …
  4. Constant Temperature Shifts. …
  5. Thermostat Is Too Old. …
  6. Thermostat Fails to Respond to Changed Settings. …
  7. Your HVAC System Short Cycles.


How do I test my furnace thermostat?

How to Test Your Furnace Thermostat

  1. Step 1: Reset the thermostat lower or higher. …
  2. Step 2: Make sure the thermostat is ON. …
  3. Step 3: Check the wiring. …
  4. Step 4: Turn breaker back on. …
  5. Step 5: Reexamine wires. …
  6. Step 6: Wrap wires together.

How do I reset my thermostat?



Here are the step-by-step reset instructions:

  1. Turn your thermostat off by switching it to the off position.
  2. Find the breaker that powers your HVAC system and turn it off.
  3. Wait 30 seconds and turn the breaker back on.
  4. Turn your thermostat back on.

How do you check if a thermostat is working?

Check the screen: Check the screen of the thermostat and make sure that it is lighted. A blank or unlighted screen could indicate a thermostat failure. Check the batteries: Many modern thermostats rely on battery power to operate. If the screen is blank or unlighted, a battery change could solve the problem.