How to run your furnace when the power goes out?

Author: Mortimer Schneider  |  Last update: Monday, June 15, 2026

Portable Generator Connect a heavy-duty double-pole, double-throw switch to the furnace, along with a power inlet receptacle. 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.

How to run a furnace when the power is out?

You can wire the furnace to use a cord and plug. Then switch the disconnect switch to a receptacle. Then in an emergency you can power the furnace with a portable power station. How long you want to run it is the issue, as the fan can draw a decent amount of power. See the video below.

What happens if power goes out while the furnace is running?

In summary, while a gas furnace may still produce heat during a power outage (if it has a standing pilot light), it will not be able to effectively heat the home without electricity for the blower fan and other components.

How can I heat my house during a power outage?

Wood stoves, coal stoves, pellet stoves and fireplace inserts are all popular options for heating North American homes without electricity. For homes where gas is available, there are through-the-wall vented thermostatically-controlled heaters available that operate without electricity.

How can I heat my house when the furnace goes out?

HOW TO KEEP WARM WHEN YOUR FURNACE GOES OUT
  1. USE A SPACE HEATER. If a power outage wasn't the cause of your furnace going out, use a space heater to stay warm. ...
  2. USE YOUR FIREPLACE. ...
  3. INSULATE AGAINST OUTSIDE AIR. ...
  4. STAY INSIDE. ...
  5. DRESS WARM. ...
  6. KEEP MOVING. ...
  7. GET COOKING. ...
  8. SLUMBER PARTY.

Keep Your Family Warm During A Power Outage By Installing This $5 Part

Should you turn off your furnace during a power outage?

To help prevent a power surge from occurring when the power comes back on, shut off your heating system at the circuit breaker and thermostat. If you have a gas furnace, keep the pilot light lit if possible.

How to keep warm when the furnace is broken?

Heater Broken? 5 Ways to Stay Warm Until the Furnace Repairman Comes
  1. Cover Windows and Doors. Even the smallest crack in your caulking can cause you to lose heat – fast. ...
  2. Generate Heat With Your Appliances. ...
  3. Close off Unused Rooms. ...
  4. Enjoy Hot Water. ...
  5. Stay Together.

Can a furnace run without 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. You should know how to safeguard your furnace for those times when the power goes out. You should also have a backup plan for your home.

How to stay warm if power goes out in winter?

If there's no electricity or gas, you can stay warm with blankets and sleeping bags. You should stay in a small, well-insulated room with other people to help retain body heat. Find air leaks and place towels around them to reduce heat loss.

Will natural gas still work if the power grid goes down?

Your natural gas fireplace can work, even during a power outage. Discover simple steps you can take to ensure your home stays warm and cozy when you need it the most. Most natural gas water heaters work without electricity.

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.

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.

What kind of generator is best for power outages?

Propane generators for power outages provide a cleaner-burning alternative with lower emissions compared to gasoline and diesel models, making them an excellent choice for those looking for more environmentally friendly options.

What happens if power goes out while furnace is running?

Most furnaces are powered by natural gas, propane, or oil, but even with these fuel sources, they rely on electricity to operate the blower fan, ignition, and safety systems. When the power goes out, the electric components of your furnace won't function, which means it can't provide heat.

How to heat your home without electricity?

8 Alternative Heat Sources that Do Not Require Electricity
  1. Backup Generator. A backup generator produces electricity by burning gasoline or propane. ...
  2. Indoor Kerosene Heater. ...
  3. Indoor Propane Heater. ...
  4. Wood Pellet Stove. ...
  5. Use Soapstone to Preserve Heat. ...
  6. Biofuel Burner Can. ...
  7. Catalytic Heaters. ...
  8. Passive Solar Heating System.

How long will a house stay warm without power?

A house can stay warm without power for about 8 to 12 hours, depending on insulation, outside temperature, and the number of occupants generating body heat.

How do I heat my house when the power goes out?

Here are five ways to stay warm—and safe—during a power outage.
  1. If You Can, Get a Generator. ...
  2. Stay in a Southern-Facing Room. ...
  3. Seal Window and Door Leaks. ...
  4. Use a Fireplace or Another Heat Source. ...
  5. Camp Out Indoors. ...
  6. Best Portable Generators to Power Your Home. ...
  7. Best Portable Generators for Small Houses. ...
  8. Space Heaters.

How long can a house go without heat?

The speed at which it continues to decline depends on several factors, including the age and structure of your home. On average, most homes retain some warmth for about 8 to 12 hours. At this point, your indoor temperature will gradually decline, bringing it closer to the outdoor temperature.

Does heat go off when power is out?

Forced Air Heating (YES)-Forced air heating is the typical heating system with ductwork and a furnace that most homes have. This type of heating system needs electricity to operate meaning that if you have a power outage, you will also lose your heat.

How to keep a furnace running in a power outage?

Portable Generator

Connect a heavy-duty double-pole, double-throw switch to the furnace, along with a power inlet receptacle. 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.

Can I turn on my furnace without a thermostat?

The answer to the question “Will my furnace run without a thermostat?” is yes! There are certain ways that you can help your furnace run without a thermostat. With a qualified HVAC professional on your side, you will be able to quickly and easily get your furnace set up without a thermostat.

Does a furnace run on a breaker?

Some larger furnaces might use more than one circuit breaker because they require more electricity to power the unit. The average size breakers for a gas furnace are: 14 gauge wire and 15 amp breaker. 12 gauge wire and 20 amp breaker.

Can it be too cold for furnace to keep up?

When temperatures drop below zero or even below freezing for extended periods of time, sometimes your furnace can't keep up. If your home is not heating up to the temperature you've set, try lowering it a few degrees.

Will pipes freeze if furnace is not working?

If your furnace isn't working, it could increase the chances that your pipes will freeze and burst.

How do I heat my house when the heater goes out?

Use a Space Heater

While your furnace may be out for the count, a space heater can warm a room just fine. If your nearby outlet can handle it, a space heater is perfect for getting your bedroom through a cold night.

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