Most homeowners think of gas furnaces as “gas-powered machines” — and while natural gas or propane is what creates the heat, that’s only half the story. Here’s the quick answer:
Yes, a gas furnace uses electricity to operate essential components like the blower motor, electronic ignition system, and thermostat. While the gas is the primary fuel for heating, electricity is required for the furnace to start, run, and circulate warm air.
If you’ve ever lost power in the middle of a Minnesota winter and noticed your gas furnace instantly shut down, you’ve already experienced this firsthand. Understanding why your furnace needs electricity — and how much — helps you operate it safely, improve efficiency, lower energy bills, and prepare for outages.
This guide explains exactly how electricity powers key furnace components, how modern systems use energy, how operation changes during a power outage, and how your furnace affects your electric bills year-round.
How a Gas Furnace Uses Electricity
A gas furnace heats air using gas, but it requires electricity to operate the systems that manage that heat. Electricity enables the furnace to ignite, control airflow, coordinate safety features, and distribute warm air throughout the home.
What Parts of a Gas Furnace Use Gas vs. Electricity
| Component | Uses Gas | Uses Electricity | Purpose |
|---|---|---|---|
| Gas burners | ✔ | Produce heat through combustion | |
| Heat exchanger | Transfers heat to indoor air | ||
| Blower motor | ✔ | Moves air through ducts | |
| Thermostat | ✔ | Signals furnace to start/stop | |
| Ignition system | ✔ | ✔ | Lights burners without a pilot |
| Control board | ✔ | Coordinates furnace operation | |
| Flame & safety sensors | ✔ | Ensure safe ignition and operation | |
| Exhaust/inducer fan | ✔ | Vents combustion gases |
Electricity drives nearly every operational function except the combustion itself. Without it, the system cannot start or continue heating.
The Electrical Components That Make a Gas Furnace Run
A gas furnace depends on several electrical systems working together. If any one of these loses power or fails, the furnace shuts down for safety.
Thermostat
The thermostat detects room temperature and communicates with the furnace via low-voltage electrical signals. Whether basic or smart, thermostats rely entirely on electricity to send commands and manage heating cycles. Proper thermostat programming, according to the U.S. Department of Energy, can reduce annual heating energy by around 10%.
Control Board
The control board is the furnace’s central processor. It sequences startup, verifies safety conditions, controls the blower, and monitors sensors. It also shuts the system down instantly if anything unsafe occurs. Without electricity, none of these operations can take place.
Blower Motor
The blower motor uses the most electricity of all furnace components. Once the burners heat the heat exchanger, the blower pushes warm air through the ducts and into the home.
Modern furnaces often use high-efficiency ECM (electronically commutated) blowers, which adjust speed to maintain comfort and consume far less electricity than older PSC motors.
Electronic Ignition
Most modern furnaces use electronic ignition instead of a standing pilot light. Hot surface igniters and spark igniters both need electricity to light the gas. Without them, the burners cannot ignite safely.
Safety Systems
Flame sensors, limit switches, pressure switches, rollout sensors, and vent monitors all depend on electricity to detect flame presence, airflow, and heat levels. If any sensor fails or becomes unsafe, it signals the control board to shut down the furnace.
Exhaust or Inducer Fan
Before gas ignites, the inducer fan clears the combustion chamber and ensures proper venting. This small but essential fan is fully electric.
What Happens During a Power Outage?
Because nearly every operational component depends on electricity, a gas furnace will not run during a power outage. Even though gas is available, the ignition system and blower cannot operate, so the furnace remains off until power is restored.
In northern climates like North Central Minnesota, where winter temperatures can drop rapidly, losing heat during an outage can quickly become unsafe.
Many homeowners choose to install:
- Whole-home standby generators
- Professionally wired portable generator transfer systems
- Smart thermostats that help manage recovery after power returns
If your furnace doesn’t restart after power restoration, a failed igniter, blown fuse, or damaged control board may be the cause.
How Much Electricity Does a Gas Furnace Use?
While gas provides the heat, the blower motor’s electricity use can add up during long heating cycles. Electricity consumption depends on:
- Furnace efficiency
- Blower motor type
- Duct design and airflow resistance
- Thermostat settings
- How often the furnace cycles in winter
- Whether the blower is used in continuous fan mode
Heating and cooling systems are the largest energy users in most homes, especially in cold regions. The blower’s electrical load makes a noticeable contribution to your winter electric bill.
Older furnaces with PSC blower motors can draw far more electricity than modern ECM systems because they run at full speed on every cycle. High static pressure from restrictive ductwork or dirty filters also forces blowers to draw more power.
How a Gas Furnace Affects Your Electric Bill
Homeowners often assume gas furnaces have little impact on electric bills, but several factors influence electric use:
Blower Runtime
In long heating seasons, the blower may operate for hundreds of hours, especially during subzero periods.
Ductwork Resistance
Leaky, undersized, or poorly designed ducts increase pressure, forcing the blower to work harder and consume more power.
Filter Condition
Dirty filters restrict airflow, extending blower runtime and increasing energy use.
Fan Settings
Using the fan in “on” mode runs the blower continuously, dramatically raising electricity consumption.
Age & Efficiency
Older motors use far more electricity than modern variable-speed motors.
Indoor Air Quality Add-ons
Whole-home filtration and ventilation can also slightly increase electric use but dramatically improve air cleanliness. Visit our page on indoor air quality improvements for more details.
Also see: energy.gov/energysaver
Ways to Reduce the Electricity Your Gas Furnace Uses
- Use a clean, properly sized filter to reduce blower strain and improve airflow.
- Keep vents and returns unblocked, allowing air to circulate freely.
- Seal and improve ductwork to reduce pressure and improve efficiency.
- Set the thermostat to reduce unnecessary cycling; the U.S. Department of Energy notes this can save about 10% annually.
- Choose a furnace with a variable-speed ECM blower, which adjusts output and uses far less power.
- Schedule professional maintenance to keep motors, sensors, and electrical components running efficiently. Regular maintenance can improve the efficiency of a gas furnace by up to 40%.
The Minnesota Department of Commerce provides helpful guidance on improving home heating performance and reducing energy use.
Comparing Gas and Electric Furnaces (Energy Use Perspective)
Many homeowners wonder how different heating systems compare in terms of energy use. This table provides a quick reference:
Gas Furnace vs. Electric Furnace Energy Characteristics
| Feature | Gas Furnace | Electric Furnace |
|---|---|---|
| Heat Source | Natural gas or propane | Electric resistance coils |
| Electricity Use | Moderate (blower/controls) | Very high (heating + blower) |
| Efficiency Impact | AFUE rating + blower efficiency | 100% electric but expensive to operate |
| Outage Behavior | Stops working | Stops working |
| Best Climate Fit | Cold climates | Mild climates or all-electric homes |
This makes gas furnaces the most common heating choice in North Central Minnesota, where winters demand strong heating output and electric furnaces become costly to operate.
Professional Diagnosis of Furnace Electrical Use
Technicians inspect:
- Blower motor amperage and health
- Ignitor condition and electrical draw
- Control board operation
- Pressure switches and sensor circuits
- Voltage stability and grounding
- Duct static pressure and airflow
These tests reveal whether your furnace uses electricity efficiently or is being strained by airflow or electrical issues.
Homeowners experiencing rising electric bills, uneven heating, frequent cycling, or furnace hesitation should schedule an inspection through our Furnace Repair page.
FAQs About Furnace Energy Usage
Do You Need Electricity to Run a Gas Furnace?
Yes. Electricity powers the blower, ignition, thermostat, control board, and safety systems. Without electricity, the furnace cannot operate.
Why Doesn’t My Gas Furnace Work During a Power Outage?
Because its essential electrical components shut down. Even though fuel is available, the furnace cannot ignite or circulate heat without electric power.
What Part of a Gas Furnace Uses the Most Electricity?
The blower motor uses the most electricity, especially in winter when heating cycles are long.
Will a Gas Furnace Work Without Electricity?
No. During a power outage, the ignition system, blower motor, thermostat, and control board lose power, and the furnace shuts down. Backup generators are the only reliable workaround.
Does a Gas Furnace Use a Lot of Electricity?
Relative to electric heating systems, a gas furnace’s electric use is modest, but the blower can still draw substantial power during long heating seasons. Factors such as airflow restriction, duct design, and blower type influence electricity consumption.
How Do I Know if My Furnace is Gas or Electric?
A gas furnace has a gas supply line, combustion chamber, burners, ignitor, and venting. Electric furnaces have heating elements and no gas piping.
Get Expert Help with Furnace Power Use, Efficiency, or Outage Preparedness
If you’re unsure how much electricity your furnace uses, concerned about winter efficiency, or planning for backup power during outages, we can help.
Neighborhood Plumbing, Heating, A/C & Electrical provides expert diagnostics, furnace tune-ups, high-efficiency upgrades, and guidance on safe generator integration — all tailored to the needs of homes in North Central Minnesota.
Schedule service or request an evaluation today through our Contact Us page.