Do I need to reset my furnace after a power outage?

Author: Ernestina Bartoletti  |  Last update: Thursday, May 21, 2026

A System Reset Is Necessary A furnace not working after a power outage may need a reset, and most modern furnaces have a yellow or red reset button. You'll need to reset your furnace's breaker first. Next, homeowners with gas furnaces should turn off the pilot light and allow the gas to disperse.

Why is my furnace not working after the power went out?

You may have a faulty sensor, sticky motor, bad controller board, too many closed dampers, a blocked air return, incomplete combustion, cracked heat exchanger, blocked condensate line, etc etc. some of these things are life-critical situations. The blickenlights will tell you.

How do I reset my HVAC after a power outage?

5 Easy Steps to Resetting Your AC After a Power Outage
  1. Turn Off Your Air Conditioner from Thermostat.
  2. Reset the Circuit Breaker.
  3. Wait for at least 30 Minutes.
  4. Turn the Thermostat Back to "Cool" Mode.
  5. Wait for 10 Minutes to See the Effect.

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.

Can a power outage damage a furnace?

Regardless of the specific damage, there's a good chance a sudden winter power outage may cause some part of your furnace to malfunction. When you need a furnace repair or furnace maintenance in the Steger, Illinois or Crown Point, Indiana areas, Merts Heating & Air Conditioning has you covered.

How to Restart Your AC After a Power Outage

How do you restart your furnace after a power outage?

Reset button—The furnace can also trip its reset button when there is a power outage. It's usually a red or yellow button located inside the blower compartment near the motor. When it's tripped it pops up. Push and hold the button for a few seconds.

Do I need to relight the furnace after a power outage?

Homeowners will want to maintain a furnace protocol in the event of a power outage. For example, do you have to relight furnace after power outage? Yes, if your pilot light goes out, you will want to shut off the gas line and wait for power.

How long does it take for a furnace to reset?

Either way, restarting a furnace is a relatively simple task that takes no longer than 10 minutes to complete.

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.

Should I hit the reset button on my furnace?

Modern furnaces have several safety mechanisms that ensure they work safely while warming your home during the chilly winter months. The reset button is one of the most important, popping out whenever a problem, like an interrupted gas supply, empty oil tank, or overheating, occurs.

How do I get my heat back after a power outage?

Most residential furnaces have a red or yellow reset button that can restore their operations after a power outage. However, before you reset your furnace, you need to reset its circuit breaker. Simply go to your breaker box, switch the breaker off, wait 30 seconds, and turn it back on.

How long does it take for HVAC to reset?

Shut off your system by hitting the isolation switch, wait 30 to 60 minutes and then turn it back on. This manual reboot fully disconnects your AC unit from power, allowing all electrical components to reset.

Do I need to reset my thermostat after a power outage?

Be sure to wait for 30 minutes, as your air conditioning system will need some time to reset before you can turn it back on completely. Once the 30-minute mark has passed, you can go to your thermostat and turn your air conditioner back on from there.

Why is my furnace blowing cold air after power outage?

Sometimes, power outages can change your thermostat's settings and switch the furnace from AUTO to ON. The ON setting forces the furnace to run continuously, causing the fan to produce cold air once it finishes a heating cycle.

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.

Does the furnace turn off when the power goes out?

Furnaces may seem more reliable than baseboard or other electric heating units during a blackout. You might think that since your furnace runs on gas or oil that you'll be fine if the power goes out. Sadly, this isn't entirely true. Your furnace still relies on electricity to power itself.

How do you reset a furnace after a power outage?

All you need to do is go over to your furnace and locate a reset button. It's typically red or yellow. If it's been tripped during an outage it will probably be raised. Make sure that you press this button down to make sure that the furnace is ready to run again.

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.

What if my furnace doesn't have a reset button?

Look on the exterior sides of your furnace for a light switch. Flip that switch to shut down power to the furnace's fan and motor. Some really old furnaces won't have a switch. If your furnace doesn't have a switch, simply ignore this step and move on to turning off the breaker.

Do you have to relight a furnace after a power outage?

Sometimes, a power outage can trigger the thermostat to shut down as well. Check your thermostat and ensure it's on and set to heat. You might need to restart it and adjust the temperature high enough to trigger it to turn the furnace on.

Where is the reset button on a furnace?

In most newer systems, the reset button is conveniently located near the blower motor, which makes it easy to spot and use when needed. In older systems, however, it may be more challenging to locate the reset button on your furnace, as it can sometimes be found underneath or behind the blower motor.

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.

Will a gas furnace still work after a power outage?

Your gas furnace does not operate like a stove because it needs electricity to generate the heat necessary to warm your house. A gas furnace is ineffective during a power outage because it needs electricity to power the components that make it work.

How long to turn 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.

What to do with a furnace if the power goes out?

If the utility power goes out, flip the double-pole switch to disconnect the permanent furnace circuit, and the run a cord from the portable generator to the inlet.

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