How do you reset a furnace after a dirty filter?

Author: Lizeth Waelchi  |  Last update: Thursday, January 15, 2026

Follow these simple steps:
  1. First, turn off the power supply to the furnace by turning off the breaker in the circuit box.
  2. Locate the reset button on the furnace and press it to reset the furnace. ...
  3. If the button is popped up, press it down.
  4. Return the cover to the blower compartment and turn the power on.

How long to leave the furnace off to reset?

Leave the breaker(s) off for at least 10 minutes while the system is off and “rebooting.” After 10 minutes have elapsed, go back to the breaker box and flip the HVAC breaker(s) back on.

How do I manually reset my furnace?

5 Ways to Reset Your Furnace or Heat Pump
  1. Start With the Thermostat. In many cases, your heat pump or furnace isn't receiving messages from the thermostat. ...
  2. Use the Furnace's Power Switch. ...
  3. Flip the Furnace's Reset Button. ...
  4. Press the Heat Pump's Reset Button or Power Switch. ...
  5. Reset the Circuit Breaker.

Can I just turn my furnace back on?

If the power switch is off, you may be able to restore service simply by turning it back on. In some cases, however, a safety trigger may have caused it to shut down. If the power switch randomly shuts off, contact an HVAC system professional to check things out.

Will my furnace shut off if filter is dirty?

If your filter becomes clogged, it can cause your furnace to shut off as a safety feature to prevent damage to the furnace. To fix this problem, simply replace your air filter on a regular basis. If you have pets, be sure to change your air filter more frequently.

How to Troubleshoot and Reset a Furnace

How do you reset a furnace after dirty filter?

Follow these simple steps:
  1. First, turn off the power supply to the furnace by turning off the breaker in the circuit box.
  2. Locate the reset button on the furnace and press it to reset the furnace. ...
  3. If the button is popped up, press it down.
  4. Return the cover to the blower compartment and turn the power on.

What happens if the furnace filter is too dirty?

A dirty HVAC filter restricts airflow, which can lead to poor system efficiency, increased energy costs, and wear and tear on the unit.

How do you know if your furnace needs to be reset?

Why Your Furnace May Need To Be Reset
  1. The furnace has overheated: When your furnace runs too hot, it triggers a safety shut-off to prevent damage. ...
  2. The fuel supply is empty: Your furnace can't generate heat without fuel. ...
  3. The gas valve is shut: A closed valve blocks the fuel supply.

How do I force my furnace to start?

Checking your thermostat is the best place to start. Make sure it's set to “heat” and that you've set the temperature higher than the current room temperature. If that doesn't resolve the problem, try switching your fan to “on” to force the furnace to start working.

Why is my furnace not kicking on for heat?

Make sure your thermostat is set to “heat” and the temperature is high enough to turn on the furnace. Go to your electrical panel and check the circuit breaker. If it's tripped, reset it and turn the furnace back on. Check your furnace filter and if it's dirty replace it with a new one.

Is it safe to hit the reset button on a furnace?

Mind the safety lock. When resetting your furnace, make sure to press the button only once to avoid engaging the safety lock. Reach out to professionals. In most cases, the safest course of action is to contact your go-to HVAC company if your furnace doesn't work after a power outage.

What part of the furnace has the reset button?

Find the Reset Button – you will then need to find the furnace reset button, which is typically located inside the blower compartment, positioned on the side of the blower motor. Press the Reset Button – If the reset button has popped up, you will need to press it down to reset the furnace.

How do I get my furnace to work again?

How to Troubleshoot a Furnace: 7 Steps to Finding a Solution
  1. Inspect the Thermostat. ...
  2. Change the Furnace Filter. ...
  3. Confirm the Furnace Is Getting Power. ...
  4. Make Sure the Circuit Breaker Isn't Tripped. ...
  5. Check the Vents for Blockage. ...
  6. Make Sure the Front Panel Door Is Secure. ...
  7. Call a Professional.

How do I reset my furnace without a reset button?

Steps to Reset Your Furnace

If you can't find a switch at the furnace you can turn off the circuit breaker to the furnace at the main circuit breaker box. Wait about 10 seconds. Turn the switch or breaker back on and check the furnace to see that it has power again.

How many times can I hit the reset button on my furnace?

You should not reset the burner more than two or three times, the reason is you may be pumping some fuel into the heat exchanger that is not igniting.

How do I get my furnace to kick on?

If nothing's happening when you're expecting the whir of a blower, check the circuit breaker and fuse. At your electrical panel, make sure all switches related to the HVAC system are on. Reset any tripped breakers and replace all blown fuses, and your furnace should kick back on.

Can hear your furnace click on but it does not fire up?

Most likely, your furnace is making a clicking noise and not providing heat because your furnace's spark igniter is trying to ignite your pilot light or burners but is failing to do so. In other words, there's an ignition system malfunction that needs to be fixed. Otherwise, your furnace won't start.

Why is my furnace turning on but not igniting?

Defective Igniter or Pilot Light

If it clicks but your furnace won't ignite after the combustion cycle, the electronic ignition systems probably need to be replaced. In cases where the furnace ignition starts normally but only stays on for a few minutes and then goes out, a new pilot light likely needs to be installed.

How long to hold the reset button on a furnace?

Turn the power back on, then the main gas supply. Press and hold the reset button for about 30 seconds. Raise your thermostat to the desired temperature. This should ignite your furnace.

Why is my furnace not turning on with the thermostat?

The thermostat may have a dead battery, so replace them with fresh ones and try again. Your furnace may turn on right away after this. If it doesn't, you may have a faulty power circuit. Have an HVAC professional diagnose this issue, and provide you with professional recommendations.

Can a dirty filter stop a furnace from working after?

Dirty Furnace Filters

This blockage can cause the heat exchanger to overheat and the furnace to stop functioning properly. Filters should be changed every three months or as recommended by the manufacturer. Watch our video on how to change your furnace filter for a step-by-step guide.

Is no furnace filter better than a dirty one?

NO. A furnace filter has a critical job to perform and a filter cannot be run without one. For a furnace to work properly, it should always be equipped with a clean, working filter. As we'll see, a dirty filter can cause problems, and so can having no filter at all.

Can a dirty filter cause a furnace to short cycle?

Dirty Air Filters

So, the furnace is triggered to stop, then it cools down only to fire back up again. This short cycling continues to repeat until the furnace receives the airflow it needs. Dirty air filters are one of the most common reasons behind furnace short cycling.

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