Any standard house furnace would either be a gas furnace or an electric furnace. Sometimes, in industrial and commercial use, oil furnaces are also used.
During the chilly months, there is no appliance more important than the heating appliance in our homes and the furnace is just one of them. When power is out, many wonder if the furnace can be run with a generator.
Can you run a furnace with a generator?
You can run a furnace with a generator as long as the power requirements for the two are compatible. An electric furnace requires a lot more wattage to run on a generator compared to a gas or oil furnace. With the right precautions, it is best to use the generator for a few hours to run the furnace.
You can surely run a furnace with a generator. But you need to make sure that you follow the capacity of both. This way, you can easily run the furnace with the help of the generator.
Gas furnace:
A gas furnace runs on natural gas that is transferred from outside to your home’s gas furnace. You can conveniently use a generator to run a gas furnace, however, it is vital to follow all the safety precautions and rules.
For one, it is most crucial that the power of the generator is enough to supply the necessary power to the generator. The number of watts the generator should be would largely depend on what the generator’s horsepower is.
Another precaution when running a gas furnace on a generator is having the generator placed outside. This would make sure the buildup of gases used by the generator has a safe passage to go.
It is also important that you install a transfer switch for the operation. Since the installation work is intricate, have a professional complete the installation for the switch.
Electric furnace:
With the help of heating elements and a coil, electrical energy is changed to heat energy in the operation of an electric furnace.
In the case of electric furnaces, the power requirement from a generator is much higher, at least 150000 watts to be exact.
When running an electric furnace with a generator, you may want to dedicate one generator to back your electric furnace.
Due to high power requirements, the other appliance in your home might not be able to get the backup from a generator.
You may also want to keep in mind that running an electric furnace on a generator is also considerably expensive, unlike the use of natural gas in regards to gas furnaces.
Oil furnace:
Oil furnaces are greatly similar to that of a gas furnace except that the fuel used is oil instead of natural gas.
You can certainly use a generator to run an oil furnace when the power in your area is out and it uses the least amount of power among the three kinds of a furnace.
In the matter of an oil furnace, a generator that is about 800 watts should be powerful enough to keep the gas furnace running on backup.
Is it safe to run a furnace off a generator?
One of the wisest questions to ask before powering a furnace with a generator, no matter what kind of furnace it is, is asking whether it is safe enough and whether there are any potential risks.
It is only safe to run a furnace off a generator if certain precautions are taken and rules are followed. The primary step to ensuring that the furnace that is being run on the generator does not malfunction or turn off is ensuring correct power levels.
You’d need to make sure that the power on the generator is well above what the furnace’s fan horsepower is. Other than that, it is equally important to keep the generator outside. Even if there is no space outside, a well-ventilated spot is mandatory.
This is important to keep harmful gases away from the house. Some people also use a carbon monoxide detector to keep track of what they are inhaling.
Using multiple, outdoor-safe cords is highly important to keep the furnace and the generator safely connected.
Can a generator damage a furnace?
If you’re aware of the term “dirty power” associated with a generator, it is the power that fluctuates repeatedly and has the potential to cause damage to the furnace.
There is a reason why professionals advise us to be careful when running a furnace on a generator. This is because, if a furnace is powered with a generator for longer periods without necessary precautions, there is a risk of damaging the furnace.
Another potential damage is trying to power a furnace with a generator that is already running too many appliances.
Hence generator is meant to only provide backup power for temporary use. That is, for the time when the main power is out, you’d not want to freeze during the chilly months.
Turning up the generator and connecting it to the furnace would ensure that the house keeps warm. Running the furnace on a generator for long hours is when the furnace might get affected by dirty power.
How many watts does a home gas furnace use?
To understand the correct wattage, use, and power requirements of your furnace, it is important to know what kind of furnace is in use and what power fan is installed in the furnace.
To a lot of users’ convenience, the home gas furnace does not use much power and hence can be run on generators quite easily. Minimally, a home gas furnace would use about 600 watts of electric power.
This typically means that when a gas furnace is turned on, there is hardly any difference in other appliances in the house. However, the scenario is different when the same gas furnace is run on a generator.
If you have a smaller-sized generator, you may want to run other appliances along with the gas furnace.
You may also want to keep in mind that while the running watts that a home gas furnace is 600 watts, it would require about 1000 to 1600 watts to start initially.
How big of a generator to run a gas furnace? What size generator do I need to run a furnace?
If you are willing to spend on a generator because you don’t want to go through the chills as your power goes out, you may have to do your homework well when it comes to the generator size.
Typically, a generator size and wattage use would vary greatly, depending on what needs to be powered. For instance, for a quarter horsepower fan of a furnace, no more than 800 watts of running power from the generator would be enough.
A 1600 starting voltage for the generator would get the furnace going. However, not all furnaces have the same requirements.
Whatever the power requirement for your furnace, the generator should have twice the power capability since generators operate at half of their potential power usage
3500-watt generator:
With a 3500-watt generator, it is possible to run small home gas or oil furnaces that would require about 1000 watts to start and about 600 to 800 watts to run.
You may want to keep in mind that this size of generator would not power a lot of appliances, neither would it back up for too long.
4000 watt-6000watt generators:
While a 4000-watt generator is not enough to back an electric gas furnace, you can still run a gas furnace along with a few household appliances.
100000 watts or more:
If you are planning to run an electric furnace, you might require a big, powerful generator of at least 10000 to 250000 watts depending on the size of the electric furnace.
How to run a furnace with a generator? How to power a gas furnace with a generator?
Here is what you’d need to do to power and run a furnace with a generator:
Place it outdoor:
If yours is a portable generator, place it outside and as far away from the house as possible.
Be sure to keep the electricity off as you begin the process and this can be done through the circuit breaker.
Install transfer switch:
Next, you would need to have the transfer switch installed to make the connection.
Use safe extension cord:
Use outdoor-safe extension cords to connect the generator to the furnace.
Rewire the cord:
Rewire the cords as you require and plug the generator into the furnace.
Final Thoughts
You can use a generator to run a furnace with the right precautions. It is important to keep the generator placed outside and use a generator that is at least twice the power requirement of the furnace. home gas furnaces would require no more than 800 watts to run on a generator.