Gas vs. Electric Furnace: Costs, Power Use & Efficiency

Many homeowners think their gas furnaces don’t use electricity.

However, that’s not entirely true. 

While natural gas powers the heating process, your furnace still relies on electricity for the blower fan, ignitor, and control board. So, how much power does a gas furnace use? 

Well, that’s the question we from homeowners quite often, especially when they’re trying to figure out how to make their heating systems more energy-efficient. Beyond gas, the energy usage of a gas furnace relies pretty heavily on electricity.

Having a keen understanding of your gas furnace’s power consumption can help you make more informed decisions on how you use your system and your overall furnace electricity cost. 

Looking to improve your furnace’s efficiency or lower energy costs? Check out our affordable maintenance plans!

Does a Gas Furnace Use Electricity?

As we mentioned, yes, gas furnaces use electricity for select components, including:

• Blower motor: This motor circulates heated air throughout your home. 

• Ignitor or pilot light: While your furnace uses gas to create the heat, the ignitor or pilot light requires electricity to start it. 

• Control board and safety sensors: The control board works by regulating your furnace to make sure it’s operating as it should. It also comes equippe with safety sensors to prevent malfunctions.

• Thermostat operation: While your thermostat controls your furnace’s temperature, it must use electricity to communicate with the system.

Now, even though gas furnaces use less electricity than electric furnaces, they can still have an impact on your energy bills.

How Many Amps Does a Gas Furnace Use?

In terms of the amp draw for your gas furnace, each powered component requires a certain amount of electrical energy. Let’s take a look at what you can expect from the typical amp usage of your run-of-the-mill gas furnace:

• Blower motor: Between 7-15 amps depending on its size.

• Ignitor: 3-5 amps, but only during the startup phase.

• Control board: These units are quite efficient and usually consume less than 1 amp

• Total average: On average, your gas furnace likely draws between 10-15 amps when operating

The exact furnace amp draw will depend on a number of factors, such as:

• Furnace size and efficiency rating: Larger and more efficient furnaces often draw more amps

• Blower motor speed settings: Higher-speed blower motors use more electricity.

• Heating demand: If you’re dealing with freezing temperatures or if the system is running for long periods, your furnace’s electricity usage will naturally increase.

It’s worth noting that most models need a 15-amp or 20-amp breaker, though some high-efficiency models need dedicated circuits to get enough power. If you’re installing a new model or upgrading your current one, it’s important to know your gas furnace electrical requirements.

How Much Power (Watts) Does a Gas Furnace Use?

Power consumption is often measured in watts, and with some simple math, it’s easy to calculate the power usage of a furnace. Here’s a quick formula:

Watts = Volts × Amps

Residential gas furnaces typically operate at 120V. So, for example:

• 10 amps × 120V = 1,200 watts (1.2 kW) per hour

So, if your furnace runs for five hours per day, its energy consumption would be:

• 1.2 kW × 5 hours = 6 kWh per day

• 6 kWh × 30 days = 180 kWh per month

At an average rate of $0.15 per kWh, this means your furnace would cost around $27 per month to run. 

While this doesn’t sound like much, the energy consumption of a gas furnace over the course of months can add up, which is why it’s important to think about optimizing your heating system.

Want a more efficient heating system? Schedule a furnace tune-up with Miller’s Heating & Air!

How to Reduce Your Furnace’s Energy Consumption

There are several practical ways you can reduce your furnace’s energy consumption without shutting it off and toughing out the cold. Here are some of our favorite energy-saving furnace tips:

• Replace the air filter regularly: If your filter is clogged, your blower will have to work harder, meaning your furnace will use more electricity. Replace it with a fresh filter for better airflow!

• Upgrade to a high-efficiency gas furnace: Modern high-efficiency furnaces use less power. We always recommend looking for ENERGY STAR-rated models for the best savings.

• Install a programmable thermostat: With a programmable thermostat, you can automatically adjust temperature based on your schedule, so it’s not on when you don’t need it.

• Improve home insulation: Proper insulation is th best way to prevent heat loss in your home. 

• Schedule annual HVAC maintenance: Scheduling regular professional maintenance can keep your furnace running at peak performance.

With the steps above, you can cut back on your monthly energy bills and keep your home warm and comfortable.

Lower your heating costs with professional furnace maintenance! Book a service with Miller’s Heating & Air today.

Frequently Asked Questions (FAQs)

Can a gas furnace run without electricity?

No, modern furnaces need electricity for the blower fan, ignitor, and thermostat. If the power goes out, so does your furnace, unless you have a backup generator.

Will a gas furnace work during a power outage?

Unless it’s connected to a generator, no. That’s why we recommend installing a backup power source for emergencies. 

How do I know if my furnace is using too much electricity?

If you have higher-than-normal energy bills, longer heating cycles, or frequent breaker trips, it might be an issue with your furnace’s electricity use. The best way to know is to call a professional to come and inspect.

Should I turn off my furnace when not in use?

Rather than turning it off completely, lower your thermostat to save energy, so you can still enjoy a warm home.