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

Author: Louie Jones  |  Last update: Thursday, April 23, 2026

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.

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

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.

What happens to a gas furnace when power goes out?

During a power outage the furnace electronics cannot function. The fans also cannot function. The furnace will not start or run.

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.

Do I need to relight my furnace after gas shut off?

Any time the gas goes off our guys have to do a relight. If it does move that means either you have a leak or you forgot one of your appliances runs on gas (it happens a lot) the service tech will then have to do a leak investigation . If no gas leaks by he is good to relight and will relight your appliances.

Why is My Furnace Not Working After a Power Outage?

Do I need to relight my furnace if the power goes out?

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. Let's take a look below at some steps you can take to stay safe if your furnace loses power.

Can I turn my gas back on myself?

Electric Bonding or Grounding

NOTE: Once you have shut off the natural gas at the meter, do not try to turn it back on yourself.

Why is my furnace blowing cold air after a 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.

Where is the reset button on my furnace?

In most newer systems, the button is often directly next to the blower motor, while in older systems, it may be harder to spot as it is sometimes underneath or behind the motor. The reset button is often made of yellow or red plastic and marked with a large “R ” to make it easier to spot.

Is it safe to turn off power to furnace?

Ultimately, there are very few situations where shutting off your system will lead to lower utility bills or savings. That's because adversities and potential damage usually arise when you power off your furnace. During winter, it's especially risky to keep your furnace off for any period.

How to run your furnace when 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. The double-pole, double-throw switch prevents the portable generator from back-feeding the entire house or, worse, the utility's system.

Is it safe to restart furnace?

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.

How to turn a gas furnace back on?

How to Re-Light Your Furnace
  1. Step 1: Turn Off Your Furnace. ...
  2. Step 2: Read the Manufacturer's Instructions. ...
  3. Step 3: Locate the Gas Valve. ...
  4. Step 4: Hold Down the Reset Button. ...
  5. Step 5: Light the Pilot Light. ...
  6. Step 6: Turn Your Gas and Furnace Back On. ...
  7. Step 7: Observe the Furnace.

Should you reset breaker after power outage?

Short-term power failures

Check your main fuses or circuit breakers to see if they have blown or tripped. Replacing a fuse or resetting a circuit breaker may restore your electricity.

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 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.

Where is the emergency furnace switch?

Gas Furnace - The emergency switch is typically a red switch located on or near the furnace unit. It may be mounted on the side of the furnace or on a nearby wall. Heat Pump - The emergency switch for a heat pump is typically a red switch located near the outdoor unit. It may be on the unit itself or on a nearby wall.

How to relight a furnace after a power outage?

Steps To Relight Furnace After Power Interruption
  1. Look at the Control Panel. Your furnace will have a control panel that regulates the system's functionality. ...
  2. Determine the Reason for the Power Outage. ...
  3. Take Safety Precautions. ...
  4. Press the Reset Button. ...
  5. Check the Thermostat and Breaker Panel.

What happens to furnace during power outage?

Do Gas Furnaces Need Electricity? Like most modern appliances, your gas furnace does use some amount of electricity to operate. Unfortunately, this means that your gas furnace will not work during a power outage.

Can a power surge affect a furnace?

A power surge can have an effect anything that uses electricity. And, when it comes to big ticket items like an air conditioner, circuit board or furnace, it can end up costing you a lot of money.

How do I reactivate my gas?

If you have a traditional gas meter

To switch your power back on, insert your payment card into the meter. You'll be asked to press and release button “A”. This will turn the gas back on.

How to turn gas back on after shut off?

Steps for turning gas back on
  1. Ensure that all your gas appliances and pilot lights are turned off.
  2. Return the gas safety shut-off valve at the gas meter to the 'on' position (12 o'clock position). ...
  3. Re-light any pilot lights by following the appliance manufacturer's instructions.

Where is the gas shut off for my house?

Your main shut off valve is located just before the gas meter. This is called your “street side valve”.

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