Choosing Heat & Airin Washington
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What are your choices in a house with a gas furnace?

Updated . Sources checked November 3, 2026.

A gas furnace house in Washington usually has time, because a working furnace forces no decision until it or the air conditioner wears out. ENERGY STAR treats a furnace over 15 years old or an AC over 10 as a prompt to evaluate, not an order to replace. Know your options before the failure, since a no-heat day is a poor time to shop.

A brick-and-frame farmhouse with an enclosed front porch at the Meyer Farmstead near Vancouver, Washington.
A brick-and-frame farmhouse with an enclosed front porch at the Meyer Farmstead near Vancouver, Washington.

What to decide, in this order

  • New gas furnace or heat pump on the West side?

    The west side version: mild winters and a gas price that has moved.

    New gas furnace
    Furnace has failed, cooling isn't wanted, and budget is tight
    Heat pump
    Cooling matters, or an income-qualified PSE gas rebate is on the table
    A modern condensing gas furnace in a closet, with white PVC vent pipes and metal ducts.

  • Should a Spokane house have a furnace or a heat pump?

    The east side version, where the cold is a real test.

    Gas furnace
    Gas homes replacing a failed furnace, with little interest in summer cooling
    Heat pump with back-up
    Electric-heat homes, and gas homes that also want cooling
    An outdoor heat pump unit against a brick wall, with driven snow stuck to its side.

  • Dual fuel or all electric: which heat pump setup fits your house?

    Keep the furnace as back-up and add a heat pump where the AC would go.

    Dual fuel (heat pump plus furnace)
    Houses with a gas furnace that is still relatively new
    All electric (heat pump plus electric back-up)
    Houses with no gas, or a furnace at the end of its life
    A worn two-storey old house with a pickup parked in front, in Spokane's Hillyard district.

  • Your furnace is fine but you have no AC: AC or heat pump?

    Furnace fine, no cooling, and a new outdoor unit is on the table.

    Central AC
    You want only summer cooling, and a bid shows a clear gap
    Heat pump, furnace stays
    You want cooling plus a second heat source for mild days
    A large grey and white Craftsman bungalow with a planted front bank on a sunny September day in Wallingford, Seattle.

  • Your AC died: replace it, or install a heat pump instead?

    The AC just failed, and the replacement could also heat.

    New central AC
    Houses with a sound furnace and no wish to change their heating
    Heat pump in its place
    Houses wanting cooling plus heat from one outdoor unit
    A square central-air condenser on a concrete pad beside a brick wall and chain-link fence.

  • Should you repair your furnace or AC, or replace it?

    Age is a prompt, and the ducts may be the real trouble.

    Repair it
    Younger equipment, one clear fault, sound ducts
    Replace it
    Older equipment, repeat faults, or rooms that never felt right
    A big square two-storey house with deep porches and a summer lawn in Walla Walla.

  • Should you seal your ducts or replace them?

    Leaks can cost more comfort than an old furnace does.

    Seal and insulate
    Ducts that are whole but leak at joints and seams
    Replace the runs
    Torn, crushed or disconnected runs, or a new system that needs different ducts
    AI-generated picture: insulated round ducts hung below floor joists above black plastic sheeting in a crawl space.

  • Gas or electric heat for a new Washington house?

    What Washington's code favors if you are building, not replacing.

    Heat pump
    Most new builds, west side especially
    Heat pump with gas back-up
    East-side builds with gas at the lot
    Gas furnace
    Builders with gas service confirmed and credits found elsewhere
    Newer two-storey houses stepping up a hillside above a dry park in Pullman, under a pale sky.

What has changed for gas houses?

Three things, and gas service ending is not one of them.

  • Price. EIA's annual Washington residential gas price went from $12.72 per thousand cubic feet in 2024 to $17.62 in 2025. On our running-cost table, a 95% furnace comes to $12.26 per million Btu delivered at 2024 prices, or about $17.00 if the 2025 jump is carried through. A Puget Sound ductless unit comes to $11.43 at 2024 prices, or about $14.10 at EIA's August 2026 rate, which is one summer month. All of that is our arithmetic.
  • The furnace rule. The federal minimum for non-weatherized gas furnaces is 80% AFUE, rising to 95% for those made on and after December 18, 2028.
  • The law. The Supreme Court struck down Initiative 2066 in full on September 17, 2026, per the court's opinion (news-site copy). Existing customers keep gas service as far as we can find. We found no utility or state statement on what follows, and will not guess.
A worn white digital thermostat on a beige wall.
A worn white digital thermostat on a beige wall.

Is there money to switch off gas?

Very little, and it depends on income. PSE listed a $4,000 rebate for income-qualified gas customers replacing gas with a heat pump (archived copy, May 2026), so confirm with the utility. Its heating page showed no gas equipment rebates (archived copy, July 2026). Most other utility offers on the utility comparison require existing electric heat. All of this is as of November 2026.

We found no official installed-price figure for a furnace or a heat pump. Ask for written bids that separate equipment, labor, electrical work, permits and duct changes. ENERGY STAR says a dual-fuel setup can come "for a modest extra cost over an AC system" if the furnace is relatively new, so ask for that line too.

Three pleated furnace-style air filters leaning against a metal wall.
Three pleated furnace-style air filters leaning against a metal wall.

What safety habits go with a gas furnace?

A yearly check, working alarms and one rule about gas smells. DOH says gas appliances should be checked yearly by a trained professional. CDC wants CO detectors near every sleeping area. If a CO alarm sounds, get everyone out first and call 911 from outside.

If you smell gas, leave first. Do not touch switches or plugs, and do not use a phone inside. From outside and away from the house, call 911 and your gas utility: PSE 1-888-225-5773 (archived copy, September 2026), Cascade Natural Gas 888-522-1130 (archived copy, December 2025), Avista 800-227-9187 (archived copy, October 2025) or NW Natural 800-882-3377. Confirm with the utility and save its number before you need it. Stay out until told it is safe.

Replacing a furnace, the gas lines and the venting all belong to a licensed contractor. Your part is changing filters and checking a breaker or switch if it will not start. Verify the contractor on L&I's tool.

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