Can A Portable Generator Run A Furnace?

Last Updated on October 2, 2023 by kiezelamquiz

generator to run furnace
The furnace allows you to keep your family warm and ensure that everyone stays at a safe and comfortable temperature throughout the winter months.

In places that are prone to blackouts, a simple power outage can cause your boiler to be inoperable until power is restored which could be anywhere from hours to days.

To keep you protected, a portable generator can be used to run a furnace.

In this post, we are going to look at how many watts your typical home furnace uses and what types of generators are going to be perfect for getting you through your power outages.

For this article, I decided to focus on gas boilers, and generators powerful enough to keep them running, while remaining relatively quiet.

If you have an electric boiler, you will need a more powerful generator, most likely 10,000W and up. When sizing a generator to run your whole house, you need to keep all of this in mind.

How many watts does a furnace use?

When it comes to shopping for a portable generator, there are a few things you need to take into consideration before buying the first one that you see.

The most important thing you will need to figure out is how many watts your particular furnace uses.

While most household furnaces use around 600 watts, your furnace may use more or less depending on the size and manufacturer.

The easiest way to find out exactly how many watts your furnace is going to use is by checking the manual or with the manufacturer and seeing what the wattage demands are.

This could be found on the back of the furnace on a manufacturer label as well.

Once you find out how many watts your furnace needs to operate, you will want to buy a generator that can support at least twice as much wattage to make sure that you are not overloading your generator.

Most generator run times are measured at 50% power usage, so if you are trying to get the most run time from your generator when powering your furnace, find one that can power twice the amount of wattage demands of your furnace.

This also allows you to be able to power up other important appliances or devices while running your furnace.

This can include a cell phone charger, CPAP machine, or other needed devices to help you get through your next blackout.

Which generators can run a furnace?

Most people who have never bought a generator before can easily get lost in the specs and demands of generators, making the process quite intimidating.

To help make your generator purchase easier for your furnace, we have taken the guesswork out and laid out 5 top-rated best furnace generators.

Let’s take a look and see which is going to be the best for you.

1. Best Quiet Furnace Generator: Honda EU2200i

Hovering around the same power ratings of the Yamaha generator, the Honda EU2200i generator is a customer favorite when it comes to portable generators.

Its ease of use and great features make it a solid choice for those who are not afraid to spend a little extra money.

Pushing out 2200 starting watts and 1800 running watts, the Honda EU2200i generator is perfect for power furnaces as it will allow you to get the furnace powered while still having around 1000 usable watts to get any other appliance powered through your blackout.

on off switch on the Honda EU2200i inverter

Operating at only 48-57 dBa, the Honda EU2200i is relatively quiet and great for residential use as using it to power your furnace will not disturb the neighbors like a larger portable generator would.

This generator is going to feature a .95 gallon fuel tank to allow for an 8.1 hour runtime at 25% load. What this means it that you can expect about a 6-7 hour run time when running a 600 watt furnace only on this generator before having to refill the tank.

The Honda EU2200i Generator Features:

  • 121cc GXR120 Engine
  • Running Watts: 1800 Watts
  • Starting Watts: 2200 Watts
  • Weight: 46.5 lbs
  • .95 Gallon Capacity Fuel Tank
  • 8.1 Hour Runtime @ 25% Load
  • (2) 120V-20A GFCI Outlets
  • (1) 12V DC Battery Charging Outlet
  • Parallel Capabilities
  • Sound Level: 57 Decibels
  • From 23 Feet Away
  • Eco Throttle Switch
  • 3 Year Commercial/Residential Warranty

Honda offers a 3 year residential and commercial warranty on the EU2200i generator for a peace of mind that you are always taken care of.


  • Lightweight
  • Eco Mode
  • Very reliable engine


  • Limited Number Of Outlets

Click here to read my full review of the Honda EU2200i generator

2. WEN 56200i Generator

Another competitor in the same range as the Honda is the WEN 56200i generator. This generator is going to offer 1600 running watts and 2000 starting watts to ensure that you have enough power for your furnace plus more.

On the Wen 56200i, you are going to notice two AC household outlet plugs, a battery trickle charger, and a set of parallel ports that rivals many of the other generators on this list.

56200I Inverter from wen sitting on grass
Producing only 51dba, this generator is also perfect for residential use. The integrated handle and 48lb weight makes it easy to move around to wherever you may need it.
Featuring a one-gallon tank, you can expect to get about 6 hours of run time by using it at 50% load. If you are running just your 600 watt furnace, this run time should extend to almost 8 hours before needing a refuel which is perfect for getting through the night.
The Wen 56201i  Generator Features:

      • 79.7cc OHV Engine
      • Running Watts: 1600 Watts
      • Starting Watts: 2000 Watts
      • Weight: 48 lbs
      • 1 Gallon Capacity Fuel Tank
      • 6 Hour Run-Time At 50% Load
      • 2-120V outlets
      • 1- USB Port
      • 1 – 12v DC Port
      • Sound Level: 51 dBa
      • Recoil Style Start

Wen offers a 2 year warranty on this generator with a customer satisfaction guarantee.


  • Budget Friendly
  • Lightweight
  • Quiet Operation


  • Lower Run Time

Click here to read my full review of the WEN 56200i generator

3. Generac 7117 GP2200I

Stepping into a little bit larger power range, the Generac 7117 GP2200I is a great choice for larger household furnaces.

Generac is a well-known generator company and has led the industry in various generator sizes.

This generator is one of Generac’s smaller generators, but it still packs quite the punch.

At 2200 starting watts and 1700 running watts, this generator is going to power just about any household furnace with ease while still having enough wattage to power other devices.

generac gp2200I control panel

You can take your choice of many different outlets on this generator as it includes 2 120V household outlets, a single USB port, a single DC Cigarette style 12V outlet, and a parallel port for expandability.

This generator will also run much longer than most with its 10.5 hour run time on the 1.2 gallon fuel capacity. It has a sound level or 58 dba which is still in the perfect range for residential use.

The Generac 7117 Generator Features:

        • 4 Stroke OHV Engine
        • Running Watts: 1700 Watts
        • Starting Watts: 2200 Watts
        • Weight: 46.6 lbs
        • 1.2 Gallon Capacity Fuel Tank
        • 10.5 Hour Run-Time
        • 2 -120V outlets
        • 1- DC Cigarette Style 12V Outlet
        • 1- USB Port
        • 1 – Parallel Port
        • Sound Level: 58 dBa
        • Recoil Style Start

Generac offers a 2 year limited warranty on this generator.


  • Light Weight
  • Mid Level Power
  • 10.5 Hour Run Time
  • Covered Outlets


  • Some negative reviews online

4. Energizer eZV2000P

Second to last but not least is the Energize eZC2000P generator. This generator rivals the other 2000 watt generators but has more features than most of them.

With 2000 starting watts and 1600 running watts, you can expect to power your furnace for 11.5 hours at 25% load. This is thanks to the 1 gallon fuel tank on the generator.

On the front of the eZV2000P, you will find covered outlets which is a huge plus. These outlets include two 120V household plugs, a 12V trickle charge, and a 12V cigarette-style port.

EZV2000P portable generator on a wooden table

You are also going to get to take advantage of an EcoMode which helps to conserve gas and bring the sound levels down to as low as 50 dba, which is one of the lowest ratings on this list.

The Energizer EZV2000P Generator Features:

          • 79cc Energizer Engine
          • Running Watts: 1600 Watts
          • Starting Watts: 2000 Watts
          • Weight: 44 lbs
          • 1 Gallon Capacity Fuel Tank
          • 11.5 Hour Runtime @ 25% Load
          • 2 -120V Outlets (Household Style Outlets)
          • 1 -12V DC Outlet
          • Sound Level: 50-59 Decibels From 23 Feet Away

Energizer offers a 3 year limited warranty to keep your investment covered.

They also have a skilled customer service team that is available to help you with ordering parts, answering questions, or helping with any technical support you may need.


  • Great value for the money
  • Various Outlet Style
  • Covered Outlets
  • Parallel Capable


  • Some QA issues reported, but fixed by energizer’s warranty

Click here to read my full review of the ezv2000P generator

5. Yamaha EF2000iSv2 Generator

Since your average household furnace is going to require around 600 watts, the Yamaha EF2000iSv2  is a great solution as it will offer the watts you need, plus enough to run another device at the same time.

This generator is going to offer 1600 running watts and 2000 starting watts which will leave you with around 600-800 extra usable watts after hooking up your furnace to power a small microwave, charge a phone, or plug in a small radio.

Yamaha EF2000ISV2 Portable Generator

This Yamaha generator is going to include 2 AC household-style plugs to allow you to hook up two different appliances at a time (wattage permitting).

You are also going to get a set of battery charging ports to slowly charge a battery if you need to.

One of the best features of the Yamaha ED2000iSv2 is that it is parallel capable which means that with a parallel cord, you can hook up another EF2000iSv2 in tandem with your original generator to get twice the power.

This allows you to create a powerful home backup supply if you ever decide to get another generator.

The Yamaha EF2000iSv2 Generator Features:

            • 79cc OHV Engine
            • Running Watts: 1600
            • Starting Watts: 2000
            • Weight: 44 lbs
            • 1.1 Gallon Capacity Fuel Tank
            • 10 Hour Run-Time
            • 2 -120V outlets
            • Sound Level: 51.5 dBa
            • Recoil Style Start

Yamaha offers a 3 year warranty on their inverters to give you protection for years to come!


  • Very Light Weight
  • Low-Mid Level Power
  • Quiet Operation


  • No major flaws

Click here to read my full review of the EF2000ISV2 generator

Frequently Asked Questions

How Do I Safely Use A Generator To Power A Boiler?

boiler home installationTo safely use a generator with a boiler, you are going to want to take into account a few different things. Some of the things you are going to want to look at are wattage ratings, placement of your generator, and the types of cords you are using with your generator.

Wattage Ratings – Ensure that the generator that you are purchasing is going to meet the needs of your furnace’s wattage requirements. As stated previously, make sure that your generator can power more than what your furnace demands to ensure it does not become overloaded.

Generator Placement – Generators use engines which create harmful exhaust fumes. Make sure that you place your generator in an area that is outdoors and in an open area for the fumes to properly dissipate. These fumes can harm you and your family if placed indoors or near windows.

Types Of Cords – When plugging up your furnace to your generator, make sure you are using high quality extension cords approved by your furnace manufacture. This is going to be a time where you may need to call the manufacturer of your generator to make sure that you are purchasing the right extension cord. Low quality cords can cause fires and electric shock.

For more safety tips, see my post about portable generator safety.

What Is The Quietest Generator To Use With A Furnace?

When using any portable generator, the sound level is something that you are going to need to take into consideration. Using a generator in a neighborhood or while camping means that you will need to be considerate of neighbors who may be disturbed by loud generators. Of the 5 generators that I have listed, the Energizer EZV2000P and the Yamaha EF2000iSv2 are going to be the quietest choices.

These both have a noise level rating of under 55 dba which should be perfect for just about any residential or camping situation.

To ensure that you are doing the most to keep your generator quiet, try placing it as far away from homes as possible to keep the noise level down even more.

There are ways to quiet it down with a custom muffler or by building a generator enclosure.

Also see my post about the most quiet portable generators.


During those harsh winter months, keep you and your family as warm as possible is important. That is why you must keep your furnace powered through black outs and power outages with a portable generator.

The generators that I have covered in this list will do a perfect job of doing this while allowing you to have extra wattages for keeping other appliances running as well.

I hope that you have a better understanding of what type of generator you will need for your furnace. To learn more about how generators work or how to operate them, check out my other articles on generators by clicking the links at the top of this page.

Let me know in the comments if you have any questions about powering a furnace with a portable generator!

Yamaha EF2000iSv2






Ease of Use



  • Easy to transport
  • Reliable Engine
  • Quiet
  • Easy to service


  • More expensive than other options is an independent review business. I am not affiliated with any manufacturers and do not accept paid reviews. When you buy through my links, I may earn a commission which helps me purchase more generators for testing. - Scott Krager

One comment

  1. I will just add to this a tiny bit, if your thinking about adding a plug in type cord to your furnace using flexable wire, I’ll mention this only because I’ve seen it being done fairly often, and a car type weather proof inverter manufacturer actually recommends doing this in there youtube videos as a permanant installation (and they even do it with too small of gauge wire) , it is an NEC violation and is not allowed unless it’s for temporary use ( less then 60 days during construction ) and even that can upset inspectors and it will also more then likely violate your warrenty on the furnace, even if it’s temporary, you should use fixed wiring, and if your in an area with frequent power outages check out some of the other blogs here about generator transfer switches. The last thing you need is a house fire to warm up your house.

    Also when it’s cold and dark finding a cord, wiring it up in the cold and dark sucks, a transfer switch to flip and simply turn on the heat is so much simpler and quicker and it’ll keep you safe and compliant to the code, and your insurance company.

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