For many American homeowners, understanding their gas furnace’s monthly electricity consumption is essential for managing utility costs and optimizing energy efficiency. Although gas furnaces primarily rely on natural gas for heating, their components—like blowers, controls, and igniters—still need electricity. This article explores how much electricity a gas furnace typically uses per month, factors that affect consumption, and tips to improve efficiency for lower bills and a more sustainable home.
Electricity Usage Snapshot For Gas Furnaces
| Component | Typical Power Draw (Watts) | Estimated Monthly Usage (kWh) |
|---|---|---|
| Blower Fan | 300–800 | 25–60 |
| Ignition System | 100–600 (briefly) | 1–2 |
| Control Panel & Sensors | 10–50 | 1–3 |
| Total Estimated | — | 30–65 |
How Gas Furnaces Use Electricity
A gas furnace’s primary energy source is natural gas, which combusts to create heat. However, several essential components require electricity:
- Blower/Fan Motor: Distributes warm air through ductwork.
- Electric Igniter or Pilot: Starts the gas combustion process.
- Electronic Control Panel: Runs safety mechanisms, thermostats, and communication.
- Sensors & Relay Switches: Manage operation and safety monitoring.
Most of the continuous electrical consumption comes from the blower fan, while igniters and electronics draw smaller, intermittent loads.
Average Monthly Electricity Consumption Of Gas Furnaces
Residential gas furnaces typically use between 300 and 800 watts per hour during active operation—primarily accounted for by the blower fan. The average furnace runs 60–90 minutes per day during the heating season, though this varies according to climate and usage.
- Low Estimate: 300 watts x 2 hours/day x 30 days ≈ 18 kWh/month
- Typical Range: 25–65 kWh/month
- High End: Older/blower-heavy models up to 100+ kWh/month
In comparison, a refrigerator might use 30–50 kWh/month, and a central air conditioner 200–400 kWh/month. Therefore, the furnace’s electric consumption is relatively low compared to other household appliances.
Monthly Electricity Cost Of Running A Gas Furnace
With an average national electricity rate of about $0.15 per kWh, the estimated monthly cost to run a gas furnace is:
- 25 kWh: $3.75/month
- 50 kWh: $7.50/month
- 65 kWh: $9.75/month
This demonstrates that operating a gas furnace is not a major contributor to electric bills for most households—the gas supply drives the main heating expense.
Factors Affecting Gas Furnace Electricity Use
Furnace Age And Efficiency
Older furnaces typically have less efficient blower motors and controls, resulting in higher energy consumption. Modern units often feature ECM (electronically commutated motors), which use 40–65% less electricity than traditional PSC (permanent split capacitor) motors.
Blower Fan Settings And Usage Patterns
Running the blower fan constantly to circulate air will considerably increase monthly usage. Using the “AUTO” setting ensures the blower runs only when heating is needed.
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Thermostat Settings
Setting the thermostat lower in winter reduces overall heating cycles, cutting electricity—and gas—usage.
Climate And Home Insulation
Colder climates and poorly insulated homes require more frequent heating cycles, leading to slightly higher electrical use for the blower and controls.
Ductwork Condition
Leaky or dirty ducts can make the blower work harder, elevating energy draw. Well-maintained, sealed ducts maximize efficiency.
Detailed Breakdown: Electricity Consumption Estimation
| Component | Wattage | Hours/Month | Est. kWh/Month |
|---|---|---|---|
| Blower Fan (mid-efficiency) | 500 | 60 | 30 |
| Ignition & Controls | 20 | 60 | 1.2 |
| ECM Blower (efficient) | 200 | 60 | 12 |
| Total (Typical) | – | – | 30–45 |
Note: Actual figures can vary depending on exact model and usage.
Comparing Gas Furnace Electricity Use With Other Systems
| System Type | Monthly Electric Use (kWh) | Primary Energy Source |
|---|---|---|
| Gas Furnace | 25–65 | Natural Gas |
| Electric Furnace | 400–1400 | Electricity |
| Heat Pump | 100–500 | Electricity |
| Oil Furnace | 20–60 | Heating Oil/Electricity |
Gas furnaces are much more efficient with electricity than electric furnaces but still require a functioning electrical system for operation. During power outages, most gas furnaces will not work, unless equipped with backup power.
What Happens During A Power Outage?
While gas furnaces use natural gas for heating, all modern units require some electricity to operate. Without power, the following components are disabled:
- Blower fan (no heated air circulation)
- Ignition system (no safe startup)
- Safety sensors and controls
As a result, your furnace will not provide heat during a blackout, unless connected to a generator capable of running the blower and controls (typically 500–1000 watts capacity required).
Estimating Your Own Furnace’s Electricity Consumption
To determine your individual usage, follow these steps:
- Check your furnace’s blower motor wattage (often listed on the data plate).
- Log average daily runtime during a winter month (often 1–3 hours).
- Multiply wattage × hours/day × days/month, then divide by 1000 for kilowatt-hours (kWh).
- Multiply by your local electric rate for cost estimation.
Or, use a plug-in usage monitor (for plug-connected models) for precise tracking.
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Ways To Improve Furnace Electricity Efficiency
There are several actionable ways to reduce your gas furnace’s electricity use:
- Upgrade to an Energy-Efficient Blower Motor (ECM): Modern motors can cut consumption by up to half.
- Seal and Insulate Ducts: Prevents blower overwork.
- Replace Filters Regularly: Ensures optimal airflow, reducing blower strain.
- Use AUTO Fan Setting: Avoids continuous unnecessary operation.
- Schedule Regular Maintenance: Identifies and fixes issues that waste energy.
- Install a Programmable Thermostat: Reduces run time when unneeded.
Each measure helps keep costs and environmental impact in check.
Environmental Impact Of Gas Furnace Electricity Use
While most emissions from gas furnaces come from burning natural gas, electricity usage still produces carbon emissions if your power source isn’t fully renewable. However, at 30–65 kWh/month, the impact is minor compared to heating.
Shifting toward efficient blowers and better home insulation further minimizes your carbon footprint while maintaining comfort.
Frequently Asked Questions
How Much Does A Gas Furnace Cost To Run Per Month Including Gas?
While electricity expenses are typically less than $10/month, gas costs are much higher and depend on climate, home size, and local gas prices. National averages put monthly gas heating costs at $50–$200+ in winter regions.
Can A Gas Furnace Run Without Electricity?
No. All modern gas furnaces require electricity for
controls, blowers, and ignition safety systems.
Is It Worth Upgrading To A More Efficient Furnace?
Yes, especially if your existing furnace is 15+ years old. Newer models are more efficient both in gas and electricity use, and often come with ECM blower motors for long-term savings.
Does Fan “On” Mode Use A Lot Of Electricity?
Yes, setting the fan to run continuously can triple or quadruple monthly electricity usage. Use “AUTO” for best efficiency.
Key Takeaways For Homeowners
- Gas furnaces primarily use electricity for the blower fan and controls.
- Most units consume 25–65 kWh/month, costing $4–$10 depending on local rates and usage.
- Electric upgrades, maintenance, and good ductwork reduce electricity waste.
- The bigger cost is natural gas consumption, not electricity.
- Improving efficiency helps keep both energy costs and environmental impact low.