Struggling to determine the right-sized generator for your furnace? Say no more.
In this insightful guide, unravel the specifics of wattage, safety margins, and additional features.
Power through the coldest days with uninterrupted warmth and comfort. Your ultimate furnace-running solution is right here!
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What Size Generator To Run A Furnace?
To run a residential furnace, a generator needs to be at least 5,000 watts for gas or oil furnaces, and at least 15,000 watts for electric furnaces. Always opt for a slightly higher wattage than the minimum to accommodate startup surges.
Generator size chart for running a furnace:
| Type of Furnace | Average Wattage |
|---|---|
| Oil Furnace | 300-700 watts |
| Gas Furnace | 600-1200 watts |
| Electric Furnace | 10,000-50,000 watts |
| Propane Furnace | 700-1500 watts |
Recommended Generator To Run A Furnace
- 3000 watts – CRAFTSMAN C0010030 Gas-Powered Generator
- 5500 watts – maXpeedingrods 86lbs Inverter Generator
- 8700 watts – Champion Power Equipment 100520 Open Frame Inverter
- 10,000 watts – DuroMax XP10000EH Dual Fuel Portable Generator
- 15,000 watts – Westinghouse Home Backup Portable Generator
Different Types of Furnaces and Their Power Requirements
There are different types of furnaces that are discussed below:
Oil Furnaces
Oil furnaces operate by burning heating oil, creating heat to warm the air.
This heated air is then pushed through ductwork, spreading warmth throughout your home.
Found in regions where natural gas is scarce, they need a consistent supply of oil, delivered and stored in a tank on-site.
Regular maintenance is essential for efficient operation and ensuring the longevity of the system.
They demand a thorough check, especially before winter, to confirm there’s enough oil and the components are in working condition.
Oil furnaces, though robust, can be a bit noisy during operation.
Gas Furnaces
Gas furnaces function by igniting a burner inside a combustion chamber, creating heat sent into a heat exchanger.
Air from your home’s ductwork is blown over the heat exchanger, warming it before it circulates back into the rooms.
These systems require a steady pipeline connection of natural gas from a utility provider.
They are popular due to their ease of use and lower operational costs compared to oil furnaces. Inspect them yearly to prevent issues like carbon monoxide leaks.
Electric Furnaces
Electric furnaces use electricity to heat elements, similar to toaster wires, which in turn warm the air circulated through your home’s ducts.
They are generally smaller and can be more easily installed in spaces without access to natural gas or heating oil.
These systems are known for their safety, as they don’t involve combustion and, therefore, carry no risk of gas leaks or carbon monoxide poisoning.
They can draw significant electrical power, potentially leading to higher operational costs, particularly in regions with high electricity rates.
Propane Furnaces
Propane furnaces share a similar operational process with natural gas models but use propane as the fuel source.
This fuel is stored in a tank on the property and must be refilled periodically. These furnaces are an option for areas where natural gas isn’t accessible.
Like other furnace types, they also require regular maintenance to check for potential leaks in the propane supply lines and ensure efficient operation.
Their usage can be more costly than natural gas, depending on local propane prices.
Factors Influencing the Choice of Generator Size for a Furnace
There are some factors that influence the choice of generator size for a furnace. Here are some of them:
Furnace Size and Capacity
When it comes to furnaces, their heating power is measured in BTUs (British Thermal Units), which essentially indicates the amount of heat a furnace can produce.
The larger your space, the colder the climate, and the less insulated your home, the more BTUs you’ll require. It’s not just about getting the furnace with the most BTUs.
It’s crucial to calculate your home’s specific heating needs, which can be precisely determined using various online calculators.
These tools consider multiple factors about your home to recommend the ideal furnace size.
Startup vs Running Watts
Every furnace has two power requirements: startup and running watts.
Startup watts are the initial surge of power needed to start the equipment, and they are higher than running watts, the continuous power required to keep the device operating.
Understanding these two values is crucial, especially if your furnace has a hard-start mechanism, which can demand a significantly high initial power surge.
Soft-start options, on the other hand, have lower startup power requirements.
Safety Margin
Even after careful calculations, it’s wise to add a safety margin to your power needs.
This extra capacity—usually 10-20% more than your estimated requirement—ensures your generator can handle unexpected surges or additional appliances without risking overload or damage.
The exact safety margin you choose will depend on your individual circumstances and risk tolerance.
Considering Other Appliances in Total Wattage
You can’t consider your furnace in isolation because other appliances also require power.
Create a comprehensive list of all electrical devices in your home, noting their individual power requirements.
Accuracy is crucial here; underestimating can lead to power shortages while overestimating can result in overspending on a too-large generator.
Evaluating Fuel Efficiency and Running Time
Fuel efficiency plays a pivotal role in choosing your generator. More efficient models will require less fuel, offering cost savings over time.
Understand your prospective generator’s running time, ensuring it can provide uninterrupted power for as long as you need, especially during extended outages.
Generator Features
Advanced features can greatly enhance your generator’s performance and convenience.
An Automatic Voltage Regulator (AVR) is crucial for maintaining a consistent power supply and preventing potentially damaging fluctuations.
The convenience of an electric start feature cannot be overstated, providing hassle-free activation with the push of a button.
Also, a low-oil shutdown feature is indispensable for preventing engine damage when oil levels are low.
Budgeting for Your Generator
When budgeting for a generator, consider both the initial purchase price and ongoing operational costs, including fuel, maintenance, and potential repairs.
Understanding the total cost of ownership helps you make an informed decision that balances both immediate and long-term expenses.
Maintenance Demands and Durability Expectations
Proper maintenance is key to ensuring your generator’s longevity and reliable performance.
Regular oil checks are a must, with changes needed every 50 hours of operation or as specified by the manufacturer.
The air filter should be inspected monthly and cleaned or replaced as necessary. Annual spark plug checks are also crucial, with replacements done as needed.
Proper storage extends your generator’s life; this includes keeping it clean, and dry, and emptying the fuel tank before storage to prevent issues related to stale fuel.
Precautions to Consider When Using Generators with Furnaces
You need to be careful and follow some precautions to avoid any hazards or problems. Here are some of them:
Use the right size generator:
You need to use a generator that can handle the power requirements of your furnace and any other appliances you want to run at the same time.
If your generator is too small, it may not be able to start your furnace or it may damage your furnace or generator.
If your generator is too big, it may waste fuel or cause voltage fluctuations.
Use the right type of fuel:
You need to use the type of fuel that is compatible with your generator and your furnace.
For example, if you have a gas furnace and a gasoline generator, you need to use gasoline as fuel.
If you have an electric furnace and a propane generator, you need to use propane as fuel. Do not mix different types of fuels or use low-quality or contaminated fuels.
Use the right type of extension cords:
You need to use heavy-duty extension cords that are rated for outdoor use and can handle the wattage of your devices.
Do not use thin or damaged cords that can overheat or cause fire or shock.
Use the right type of outlets:
You need to use outlets that are grounded and protected by circuit breakers or fuses. Do not use outlets that are overloaded or faulty that can cause fire or shock.
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Use the right type of transfer switch:
You need to use a transfer switch that can safely connect your generator to your home’s electrical system and isolate it from the utility power.
A transfer switch prevents back feeding, which is when electricity from your generator flows back into the utility lines and can electrocute utility workers or damage your generator or devices.
A transfer switch also prevents overloading, which is when electricity from the utility power flows into your generator and can damage your generator or devices.
Place the generator in a safe location:
You need to place your generator in a dry, level, and well-ventilated area away from any flammable materials, sources of heat, or sources of ignition.
You also need to keep your generator at least 20 feet away from your home, windows, doors, vents, or any other openings that can allow carbon monoxide to enter your home.
Carbon monoxide is a colorless, odorless, and deadly gas that can be produced by your generator’s engine.
You need to install carbon monoxide detectors in your home and check them regularly.
Operate the generator safely:
You need to follow the instructions and warnings in your generator’s manual and on its labels.
You also need to wear protective gear such as gloves, goggles, and earplugs when operating your generator.
You need to start your generator before plugging in any devices and turn off any devices before turning off your generator.
You need to avoid overloading your generator or running it for too long without rest.
You need to check the oil level, fuel level, air filter, spark plug, battery, and other parts of your generator regularly and perform any necessary maintenance or repairs.
Best Generator To Run Furnace
1. A-iPower AP1500i 1500 Watt Portable Inverter Generator Gas Powered
- Produces 1500 starting watts with 1200 running watts of clean and safe power for sensitive electronics, such as phones, televisions, laptops, and other electronics.
- Complete with A-iPower’s “Low idle” technology for an extended run time of 4 hours at 100% load and 6.5 hours at 50% load.
- Equipped with a low oil alert light and low oil automatic shutdown, helping keep your generator performing year after year.
- Powerful 79cc OHV 4-Stroke engine provides an abundant power supply yet runs at a super quiet operation of only 52 decibels.
- Light weight and compact at only 46 pounds, making your tailgate or camping experience as smooth as possible.
Looking for a reliable generator to run your furnace or other sensitive electronics during a power outage or while on the road? Look no further than the A-IPower AP1500i Portable Inverter Generator.
With 1500 starting watts and 1200 running watts of clean and safe power, this gas-powered generator is perfect for use in your home, RV, or during emergencies.
You’ll be able to power your furnace, phones, laptops, televisions, and other electronics with ease, without worrying about damaging them.
One of the standout features of this generator is its “Low idle” technology, which allows for an extended run time of up to 4 hours at 100% load and 6.5 hours at 50% load.
This means you’ll be able to keep your power supply going for longer, even when you need to run it at full capacity.
And don’t worry about running out of oil – the AP1500i has a low oil alert light and automatic shutdown feature, so you’ll always know when it’s time to top up or change the oil. This will help keep your generator running smoothly year after year.
Despite its powerful 79cc OHV 4-Stroke engine, the AP1500i runs at a super quiet operation of only 52 decibels.
You won’t have to worry about disturbing your neighbors or fellow campers while you enjoy your tailgate or camping experience.
Plus, at only 46 pounds, this generator is light weight and compact, making it easy to transport and store when not in use.
Overall, the A-IPower AP1500i Portable Inverter Generator is a reliable and versatile option for anyone in need of a generator to run their furnace or other sensitive electronics. With its extended run time, low oil alert, and quiet operation, you can rest easy knowing that you’ll have power when you need it most.
2. Craftsman 3000i Inverter 50 St/CSA
- Built in Handle – Easy mobility; carry with one hand
- Steady power – Our technology makes safe, clean power for your electronics
- Easy start – Start/Stop/Choke dial makes starting quick and easy
- Boost of Power – 50 percent more starting capacity allows you to do more with a smaller product
- Ultra Quiet Design with High Performance – Perfect for camping and tailgating
One of the standout features of this generator is its built-in handle, which makes it incredibly easy to move around.
You can even carry it with just one hand! Plus, with its steady power output, you can rest assured that your electronics will be safe and sound while it’s running.
Starting the Craftsman 3000i Inverter is a breeze, thanks to its Start/Stop/Choke dial.
And even though it’s a smaller product, it packs a punch with 50 percent more starting capacity, giving you a boost of power to handle all your needs.
If you’re worried about noise levels, don’t be. The Craftsman 3000i Inverter is designed with an ultra-quiet engine that won’t disturb your camping or tailgating experience.
But just because it’s quiet doesn’t mean it skimps on performance. This generator can handle all your power needs with ease.
Overall, the Craftsman 3000i Inverter is an excellent choice for anyone looking for a reliable and efficient generator.
Its easy mobility, steady power, and quiet operation make it perfect for a variety of applications, from powering your furnace to keeping your electronics charged while on the go. Give it a try and see for yourself!
3. maXpeedingrods 5500W Inverter Generator
- [Multi-Purpose Power Supply]Rated power 5000W, maximum power 5500W, basically can meet the larger power appliances (such as conventional power tool). Under power outage scenarios, it can basically provide continuous power supply for small and medium-sized households
- [Easy Start] Recoil Start and Eletric Start are configured in two starting modes, electric start is easy to operate and can be started successfully at once. recoil start can be used as an alternative starting method to recharge the built-in battery for electric start when it runs out of power.
- [Clear Digital Display]The panel is equipped with a digital display screen to monitor the data and feedback information in real time. It helps you clearly understand the fuel condition, usage, power generation status and generator condition.
- [Power More Appliances]With 2*120V 20A, 1*120V 30A, 1*120V/240V 30A dual voltage plug (can be directly connected to 220V and 240V appliances), 2*USB port to solve the output needs of conventional appliances. Large panel with many interfaces, can supply power to a larger number of appliances simultaneously without transfer switch
- [Compact Design]Makes it lighter weight in the 5KW and higher power band, and 25% weight reduction on the basis of the previous generation MXR5500, with a net weight of only 86lbs, a significant increase in portability. The longest side is 21.7 inches, making it smaller and more convenient to store when not in use.
- [Brand Warranty]Maxpeedingrods warrants all the inverter generators against defects in workmanship under normal use for a period of 2 years from the date of retail purchase by the original end-user purchaser (“Warranty Period”), and free lifetime technical support and customer service.
The maXpeedingrods 5500W Inverter Generator is easy to start with two starting modes, Recoil Start and Electric Start.
The electric start is especially user-friendly and can be started successfully at once, while the recoil start can be used as an alternative starting method to recharge the built-in battery for the electric start when it runs out of power.
The generator’s panel is equipped with a clear digital display screen that monitors the data and feedback information in real time.
This feature helps you understand the fuel condition, usage, power generation status, and generator condition.
With multiple output interfaces, including 2120V 20A, 1120V 30A, 1120V/240V 30A dual voltage plug, and 2USB ports, this generator can power more appliances simultaneously without a transfer switch.
The maXpeedingrods 5500W Inverter Generator has a compact design, making it lighter weight and more portable than other generators in its class.
It weighs only 86lbs, and its longest side is 21.7 inches, making it easy to store when not in use.
Finally, the maXpeedingrods 5500W Inverter Generator comes with a 2-year warranty against defects in workmanship under normal use and free lifetime technical support and customer service.
So, you can purchase this generator with confidence, knowing that it will be backed by excellent customer service.
4. CPE 100520 DH Series Open Frame Inverter
- Advanced Open Frame Inverter Design: 30% quieter and 25% lighter than a traditional Champion 7000-watt generator, plus this inverter only produces Clean Power, and Economy Mode saves fuel
- Electric Start: The convenient electric push-button start includes a battery
- Quiet Technology and Extended Run Time: 72 dBA is great for your next project or home backup, with 8750 starting watts and 7000 running watts for up to 10. 5 hours run time on gasoline
- Intelligauge: Monitor voltage, frequency and operating hours with ease.Use a damp cloth to clean exterior surfaces of the generator
- Champion Support: Includes 3-year limited with FREE lifetime technical support from dedicated experts
CPE 100520 DH series advanced inverter design is not only 30% quieter and 25% lighter than traditional generators, but it also produces clean power and has an Economy Mode to save fuel.
With an electric push-button start and a battery included, starting up your furnace during a power outage has never been easier.
Plus, the Quiet Technology and Extended Run Time of up to 10.5 hours on gasoline ensure that you can stay warm and cozy without any interruptions.
The Intelligauge feature allows for easy monitoring of voltage, frequency, and operating hours, while the generator’s exterior surfaces can easily be cleaned with a damp cloth.
And with Champion Support, you can rest assured that you’ll have access to dedicated experts for free lifetime technical support.
5. DuroMax XP10000EH Dual Fuel Portable Generator
- Plenty of Power – With 10,000 starting watts and 8,000 running watts, this unit can handle heavy loads from lights and a refrigerator to a home air conditioner and high amperage power tools
- Dual Fuel Technology – This generator runs on gasoline or propane, giving you the freedom and flexibility of fuel choice
- Powerful Engine – The DuroMax 439cc OHV engine is a workhorse that provides plenty of power to handle multiple jobs, from powering high voltage appliances to heavy duty power tools
- Idle Control – Lowers the RPMs of the generator when not in use, saving fuel and reducing noise. Ideal on job sites where power is used intermittently
- MX2 Technology – Get the maximum power from each of the 120-volt receptacles. Choose between operating the generator at both 120V and 240V simultaneously, or at 120V only with full power. Ideal for usage with RVs
The DuroMax XP10000EH Dual Fuel Portable Generator could be the perfect solution for you to run a furnace. This powerful generator can handle heavy loads with its 10,000 starting watts and 8,000 running watts.
One of the standout features of the DuroMax XP10000EH is its dual fuel technology. You can use either gasoline or propane as fuel, giving you the flexibility to choose the option that suits you best.
The generator’s powerful 439cc OHV engine is designed to handle multiple jobs, from powering high-voltage appliances to heavy-duty power tools.
The DuroMax XP10000EH also has Idle Control, which lowers the RPMs of the generator when not in use, saving fuel and reducing noise.
This feature is particularly useful on job sites where power is used intermittently. The MX2 Technology allows you to get maximum power from each of the 120-volt receptacles, making it ideal for usage with RVs.
Whether you need a reliable backup power source for your home or RV, the DuroMax XP10000EH is an excellent choice.
With its impressive power output, dual fuel technology, and efficient design, this generator is a solid investment for anyone in need of a dependable power source.
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FAQs About Right Size Generator To Run Furnace
How Much Wattage Is Required To Run A Home Furnace?
A home furnace is typically a light-duty appliance that doesn’t need much wattage to keep running.
Most gas-fired furnaces require around 600 watts of electricity to keep running.
Can A 2000 Watt Generator Run A Furnace?
A 2000-watt generator is powerful enough to run an oil or natural gas furnace.
What Is The Quietest Generator For A Furnace?
The YAMAHA EF2000iSv2 Gas Powered Portable Inverter will be the right option to keep the environment calm while getting the job done.
Will a 3500 watt generator run a furnace?
A 3500 watt generator can certainly run a furnace, provided the furnace is not too large or power-hungry.
Can I power my furnace with a generator?
It depends on the size of your furnace. If you have a small furnace, then you may be able to use a portable generator to power it.
Will a 1000W generator run a gas furnace?
No, a 1000 watt generator is not enough to run a gas furnace. The starting wattage for most furnaces is between 2000 and 3000 watts.
Will a 5000 watt generator run a furnace?
Yes, a 5000 watt generator will run a furnace.
Can a 6500 watt generator run a furnace?
A 6500 watt generator can indeed run a furnace, however, it is not recommended to do so for extended periods of time.
How many watts does a furnace draw?
It depends on the type and size of the furnace. Generally speaking, most furnaces will require between 3000-4000 watts to operate.
If you have a larger or more powerful furnace, it may require up to 6000 watts.
Will a 5500 watt generator run my furnace?
In general, a 5500 watt generator should be able to power a furnace without any problems.
Will a 4000 watt generator run a furnace?
If you have a 4000 watt generator, you should be able to run a furnace without any issues.
Final words
Whether you want to be prepared for a harsh winter or a power outage, a generator is an all-in-one solution.
Throughout the guide, we have explained what size generator to run the furnace and offered some ideas for determining your own.
Hopefully, getting the right size generator for the furnace will be a straightforward task for you, so you can enjoy warm air on those cold days.
