Why does my furnace not kick on sometimes?

If your furnace is not turning on you should first check if the filter is clean. Dirty filters cause insufficient airflow and can prevent the furnace from starting. Other reasons it won’t start can stem from improper thermostat settings, forgetting to turn on the gas line, or faulty pilot light.

Will a bad thermostat cause the furnace not to work?





Thermostat Isn’t Working



One of the most common furnace problems is a malfunctioning thermostat. A sure sign your thermostat isn’t working properly is if your fan is constantly running. This will cause your thermostat battery to run, and cause your furnace to work inefficiently.

Why does my furnace not turn on when its cold?

Blown fuse.



Your furnace uses gas to produce heat, but it also uses electricity to blow air throughout your home. If the fuse to your furnace is blown, your system will not turn on. Check your circuit breaker and make sure that the switch for your furnace is in the “on” position.

Why do I keep having to reset my furnace?

A furnace reset button is an important feature included with your HVAC system. Designed to quickly shut the unit off, the function is key to safely heating your home. If your furnace reset button keeps tripping, it’s likely that your furnace is overheating. This may indicate a need for furnace repair services.

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.





Why does it take so long for my furnace to kick on?

Your furnace might not turn on due to a burnt-out pilot light or a dirty flame sensor. A furnace may also be slow-starting because of an issue with its thermostat, so you may need to call in an electrician. Regardless, keep your furnace clean, and don’t forget to schedule an annual check-up before the winter season.

How do you tell if a thermostat is bad for a furnace?

The AC or furnace won’t come on: When you set the thermostat above or below the ambient temperature, you should hear a click, and the AC or furnace should kick on almost immediately. If you make changes at the thermostat and nothing happens, that’s the first sign you have a bad thermostat.

How do you know if your thermostat is short cycling?

Furnace short cycling refers to the switching on and off of your furnace system without reaching the set temperature on the thermostat. And for those experiencing short cycling, you may notice suddenly that your home isn’t as warm as it should, leaving you and your loved ones cold and uncomfortable.

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 you know you need a new thermostat?

Signs You Need a New Thermostat

  1. Heating or cooling system will not turn off or on.
  2. The temperature reading is incorrect.
  3. Recent spike in your energy bill.
  4. Frequent temperature fluctuations.
  5. Thermostat is 10 years old or older.



How long do furnace thermostats last?

Most thermostats can last 10 years. After 10 years, they can show signs of age and wear, which means it’s time to replace it. Common problems with bad thermostats include faulty sensors, digital screens, etc. If the thermostat goes bad, it can cause your HVAC system to run continuously or not run at all.

Will a furnace work without a thermostat?

It will only shut off if you disconnect the wires. This wastes energy and could cause your system to overheat and quit working. You’ll need to replace the thermostat as soon as possible.

Why is my thermostat not turning the heat on?

If your heating system will not turn on, the first thing you should do is check the thermostat. The thermostat’s battery may have gone bad, causing it to power off. If your thermostat is hardwired, a power surge, brownout, or brief power outage may have caused the thermostat to lose its settings.

Can low battery cause thermostat problems?



Having a low battery can cause all kinds of bad readings on the thermostat, which means the thermostat may kick on when it’s not supposed to, the room temperature may be incorrect, and the central system may not work at all.

How do I know if my thermostat needs new batteries?

The most obvious sign that you need to change your thermostat batteries is when the thermostat literally tells you the batteries are about to die! Most programmable models will now flash a low battery warning, usually about a month or two before the battery completely dies.

How can I test my thermostat?

Quote from the video:
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How often do you need to change thermostat battery?

about once every year



As a rule, thermostat batteries will need to change about once every year. If you periodically change them, you shouldn’t have any problems maintaining control of your thermostat.