Gas vs Electric Furnace in Washington: Complete Comparison Guide

When your furnace needs replacement—or you're building new—Washington homeowners face a consequential choice: natural gas or electric heat. Unlike other regions where gas dominates, Washington's clean electricity grid, mild climate, and evolving building codes make this a genuinely competitive decision.

This guide compares gas and electric heating for Washington homes, including operating costs with our specific energy prices, efficiency considerations, and how state climate policies may affect your long-term investment.

Quick Comparison: Gas vs Electric Furnace

Feature	Natural Gas Furnace	Electric Furnace	Heat Pump (Electric)
Equipment Cost	$2,500–$6,000	$1,500–$3,500	$4,000–$8,000
Installation Cost	$2,000–$4,000	$1,000–$2,500	$2,000–$5,000
Total Installed	$4,500–$10,000	$2,500–$6,000	$6,000–$13,000
Efficiency	80–98% AFUE	100%	200–400% (COP)
Operating Cost/yr	$800–$1,400	$1,200–$2,200	$500–$1,000
Lifespan	15–25 years	15–20 years	15–20 years
Carbon Emissions	Moderate-High	Very Low (WA grid)	Very Low
Requires Gas Line	Yes	No	No
Requires Venting	Yes	No	No (outdoor unit)
Maintenance	Annual	Minimal	Annual

Understanding Your Options

Natural Gas Furnace

Gas furnaces burn natural gas to heat a metal heat exchanger. A blower circulates home air over the exchanger, warming it before distribution through ductwork.

Efficiency ratings (AFUE):

• Standard efficiency: 80% AFUE
• High efficiency: 90–95% AFUE
• Condensing (premium): 96–98% AFUE

How to read AFUE: A 95% AFUE furnace converts 95% of gas energy to heat; 5% escapes through the vent.

Electric Resistance Furnace

Electric furnaces use heating elements (like a giant toaster) to warm air. Simple, reliable, and 100% efficient at converting electricity to heat.

Why 100% efficiency isn't impressive: Every watt of electricity becomes heat—but electricity costs more per BTU than gas in most situations, so total operating cost matters more than efficiency rating.

Heat Pump (The Third Option)

Heat pumps move heat rather than creating it, achieving 200–400% efficiency. They're technically electric but operate completely differently from resistance heat. Modern cold-climate heat pumps work effectively in Washington's climate.

Why include heat pumps? They're increasingly the right choice for Washington, so any honest furnace comparison must acknowledge them.

Washington Energy Landscape

Our Unique Grid

Washington's electricity is exceptionally clean:

• 70%+ hydroelectric power
• Growing wind and solar
• One of the cleanest grids in the United States
• Electric heat produces minimal carbon emissions here

Contrast: In coal-heavy states, electric heat may produce more emissions than gas. In Washington, electric is the clear winner environmentally.

Energy Prices

Washington energy costs (residential averages, 2024):

• Electricity: $0.10–$0.12/kWh (varies by utility)
• Natural gas: $1.30–$1.60/therm (volatile)

Price comparison per 100,000 BTU delivered:

• Gas furnace (95% AFUE): $1.50–$1.75
• Electric resistance: $2.95–$3.50
• Heat pump (COP 3.0): $0.95–$1.15

Bottom line: Gas costs less to operate than electric resistance. Heat pumps cost less than both.

Building Code Evolution

Washington's building codes are shifting:

• 2023 WA State Energy Code favors heat pumps
• New construction increasingly requires heat pump capability
• Some cities (Seattle, Bellingham) restricting gas in new buildings
• Incentives favor electric heat pump installation

Climate Considerations

Western Washington (Seattle, Tacoma, Olympia)

Typical heating season:

• 220–250 heating days
• Rarely below 25°F
• Mostly 35–50°F heating weather
• Very few extreme cold events

Implications:

• Heat pumps work at high efficiency most of the season
• Gas furnace backup rarely needed
• Mild climate reduces total heating costs
• Excellent heat pump territory

Eastern Washington (Spokane, Tri-Cities, Pullman)

Typical heating season:

• 280–320 heating days
• Regular sub-zero temps (multiple times per winter)
• Extended periods below 30°F
• More challenging for heat pumps

Implications:

• Cold-climate heat pumps still effective but less efficient
• Gas furnace provides reliable cold-weather backup
• Dual-fuel systems (heat pump + gas) increasingly popular
• Higher total heating costs regardless of fuel

Mountain Areas

Typical heating season:

• 300+ heating days
• Extended sub-zero periods
• Heavy snow (affects outdoor equipment)
• Most challenging heating environment

Implications:

• Gas furnace reliability valuable during extreme cold
• Heat pump efficiency drops in coldest weather
• Dual-fuel recommended for best of both
• Higher capacity equipment needed

Operating Cost Analysis

Annual Heating Cost Comparison (2,000 sq ft home)

Western Washington (mild winter):

System	Annual Cost
Gas (95% AFUE)	$700–$1,000
Electric Resistance	$1,400–$2,000
Heat Pump (cold-climate)	$450–$750

Eastern Washington (cold winter):

System	Annual Cost
Gas (95% AFUE)	$1,200–$1,600
Electric Resistance	$2,000–$2,800
Heat Pump (cold-climate)	$800–$1,200
Dual-Fuel (HP + Gas backup)	$700–$1,100

Natural Gas Price Volatility

Gas prices fluctuate significantly:

• Winter 2022–23 saw 50%+ price spikes
• Geopolitical events affect supply
• Pipeline capacity constraints in Pacific NW
• Long-term trend uncertain

Electricity prices in Washington are relatively stable (hydropower is predictable).

10-Year Total Cost of Ownership

Gas Furnace: 10-Year Cost

Cost Category	Amount
Installation (high-efficiency)	$6,000–$9,000
Annual operating (Western WA)	$8,000–$12,000
Annual maintenance	$1,500–$2,500
Repairs (typical)	$500–$1,000
10-Year Total	$16,000–$24,500

Electric Resistance: 10-Year Cost

Cost Category	Amount
Installation	$3,000–$5,000
Annual operating (Western WA)	$15,000–$22,000
Annual maintenance	$500–$1,000
Repairs	$200–$500
10-Year Total	$18,700–$28,500

Heat Pump: 10-Year Cost

Cost Category	Amount
Installation	$7,000–$12,000
Annual operating (Western WA)	$5,000–$8,000
Annual maintenance	$1,000–$2,000
Repairs	$500–$1,500
Rebates/incentives	-$1,000–$4,000
10-Year Total	$12,500–$19,500

Clear winner: Heat pumps deliver lowest total cost when incentives are factored in.

Efficiency Deep Dive

Gas Furnace Efficiency

Standard efficiency (80% AFUE):

• Exhausts significant heat through vent
• Lower equipment cost
• Being phased out by efficiency standards

High efficiency (90–98% AFUE):

• Condensing technology captures more heat
• Secondary heat exchanger
• Plastic PVC venting (not metal)
• Lower operating costs justify higher equipment cost

Recommendation: Always install 95%+ AFUE in Washington. The payback period is short given our heating season.

Electric Resistance "Efficiency"

Electric resistance is 100% efficient but that's misleading:

• All electricity becomes heat (no waste)
• But electricity costs more per BTU than gas
• And power plants have their own inefficiencies (even if WA's grid is clean)

Electric resistance makes sense when:

• No gas line available (new line = $3,000–$10,000)
• Supplemental heat for specific rooms
• Very small heating loads
• Heat pump isn't feasible

Heat Pump Efficiency

Heat pumps move heat rather than generating it:

• COP (Coefficient of Performance) measures output vs input
• COP 3.0 = 300% efficiency (3 units of heat per 1 unit of electricity)
• Efficiency varies with outdoor temperature
• Cold-climate models maintain COP 2.0+ even at 5°F

Why heat pumps win in Washington: Our mild climate means they operate at high efficiency most of the heating season.

Installation Considerations

Gas Furnace Installation

Requirements:

• Gas line to furnace location
• Combustion air supply
• Metal or PVC flue venting (through roof or wall)
• Thermostat and controls
• Ductwork (existing or new)

Complexity: Moderate-High

Washington-specific:

• Gas line permits required
• Combustion safety testing (CAZ test)
• CO detectors required
• Annual inspection recommended

Electric Furnace Installation

Requirements:

• Electrical circuit (200A service usually adequate)
• No venting needed
• No gas line needed
• Ductwork (existing or new)

Complexity: Low-Moderate

Advantages:

• Simpler installation
• No combustion safety concerns
• Lower installation cost
• Flexible placement options

Heat Pump Installation

Requirements:

• Outdoor unit placement
• Refrigerant lines to indoor unit
• Electrical circuit
• Ductwork or ductless air handlers

Complexity: Moderate-High

Washington considerations:

• Cold-climate models recommended (most of state)
• Proper sizing critical for efficiency
• Supplemental heat may be needed for coldest days
• Dual-fuel option combines with gas for extreme cold

Environmental Impact

Carbon Emissions Comparison

Per 100 million BTU delivered (Washington grid):

• Gas furnace: ~12,000 lbs CO2
• Electric resistance: ~2,000 lbs CO2
• Heat pump: ~800 lbs CO2

Why electric is so clean here: Washington's hydroelectric-dominated grid produces minimal carbon emissions. In most states, gas is actually cleaner than electric resistance—but