Decisions Heat, west side West side
New gas furnace or heat pump on the West side?
New gas furnace or Heat pump
Compared by the people who run this site. Updated . Rebates and prices checked November 3, 2026.
Choosing a gas furnace or heat pump on the West side now leans on prices and cooling. Gas prices jumped in 2025, a heat pump adds air conditioning, and rebates mostly skip gas homes. A working furnace needs no rush at all.
The verdict, by situation
If your gas furnace still works and you want cooling too
Keep it and add a heat pump instead of an AC. ENERGY STAR calls dual fuel a modest extra cost over an AC system if the furnace is relatively new. See add AC or a heat pump.
If the furnace is failing, you're a PSE gas customer, and your income qualifies
Price the heat pump first. PSE listed a $4,000 rebate (archived copy, May 2026) for replacing gas with a heat pump. Confirm with the utility.
If the furnace has failed, you don't want cooling, and you don't qualify for that rebate
Get a bid both ways. Compare a 95% AFUE furnace with a heat pump on your own rates, then read the numbers below.
If you worry that gas service is about to end
Don't choose on that. The state court struck down I-2066 on September 17, 2026 (the court's opinion, news-site copy), and gas service itself did not end.
Side by side
| Compare | Gas furnace | Heat pump |
|---|---|---|
| Efficiency basis | 80.0% AFUE minimum; 95.0% for those made from December 18, 2028 | Split minimum 14.3 SEER2, 7.5 HSPF2 |
| Cooling | None | Yes |
| Heat cost, our arithmetic | $12.26 per million Btu at 95% and 2024 gas; about $17.0 at 2025 gas | $11.43, ductless in Puget Sound, 2024 power; about $14.1 at the August 2026 rate, one summer month |
| Combustion checks | Yearly, by a trained professional | None |
| CO alarm | CDC: near every sleeping area | Same advice if any fuel burns in the house |
| Electric rebate lines | None | Few for gas homes; see below |
| Permits in Seattle | Furnace or mechanical | Refrigeration, licensed contractors |
Sources: 10 CFR 430.32, EIA prices, DOH. The cost row is our division: 2024 statewide averages, not your utility; the "about" figures use 2025 gas and August 2026 power. AFUE is a rating, not metered. Pilot homes were metered in 2008-09, duct losses aren't counted, and we have no metered West side figure for a ducted heat pump. See the running-cost page.
What would change the answer
- Your own gas bill is far from the state average. PSE's per-therm rates couldn't be confirmed here, so use your bill.
- You don't qualify for the PSE offer and your furnace is new. Then ripping out a working system is hard to justify on these numbers.
- Your ducts leak. ENERGY STAR says fixing air leaks and ducts first can solve the real problem.
- You have a panel with no room. Ask for that line in the bid, and check whether HEAR covers you.
- You live east of the Cascades. Read the Spokane version, where Inland Empire savings are lower.
- A code or utility rule changes. Nothing we found settles local gas limits or PSE service changes after I-2066.
What it costs, with dates
EIA's Washington residential annual price was $12.72 per thousand cubic feet in 2024 and $17.62 in 2025. Use annual figures, since low-use summer months overstate the winter price. Electricity averaged 14.63 cents per kWh in August 2026.
Rebates, as of November 2026:
- PSE: $4,000 for income-qualified gas customers switching (archived copy, May 2026). A Trade Ally or REP installs, and the contractor removes or decommissions the old equipment. Confirm with the utility.
- PSE electric customers: a distributor discount of $300 to $600 (archived copy, June 2026), with part going to the distributor or contractor. Confirm with the utility.
- Tacoma Power: $1,000 for variable speed from non-electric heat.
- Snohomish and Clark: their rebates are written for electrically heated homes.
- Income-based: HEAR through local administrators, at or below 150% of area median income.
We found no official installed-price figure for a furnace or a heat pump. Ask each bidder to separate equipment, venting or refrigerant work, electrical, ducts, gas line changes and permits. See whether to wait for a rebate, the gas furnace house guide and the West side list.
Who does the work
Both jobs belong with a registered contractor you've looked up on the L&I tool. Gas piping, burners, vents and refrigerant are never reader work. Unincorporated King County requires a permit to install or replace furnaces, and Seattle has separate furnace and refrigeration permits. Your part is filters, a clear space around the equipment, a breaker check, and booking the yearly service DOH recommends for gas appliances.
What does I-2066 mean for a furnace you buy now?
It no longer applies. The Washington Supreme Court held the initiative unconstitutional in its entirety on single-subject grounds (the court's opinion, news-site copy).
Existing customers keep gas service, and we found nothing saying otherwise. We also found no statement from state agencies on what comes next, so this page makes no forecast. Choose on bills, comfort and the state of your furnace.
Does the 2028 federal rule force your hand?
No. The 95.0% AFUE minimum applies to non-weatherized gas furnaces made on and after December 18, 2028. A furnace made before then can still meet the 80.0% floor, though the higher rating burns less gas for the same heat.
What should you do if something seems wrong with a gas furnace?
Act on the alarm or smell, and leave the furnace alone. If a CO alarm sounds, get everyone out first and call 911 from outside.
If you smell gas, leave first. Don't use switches, plugs or a phone inside. From outside and away, call 911 and your gas utility. Published numbers include PSE at 1-888-225-5773 (archived copy, September 2026: PSE leak page), Cascade at 888-522-1130 (archived copy, December 2025: Cascade emergency page) and NW Natural at 800-882-3377. Confirm with the utility and keep your number handy before you need it.
Parts and examples
Plumbing Supply and More, which shares an owner with this site, has a category for unitary HVAC equipment. Use it to compare what a bid names. This equipment is for a licensed contractor to install, and none of it is a homeowner job.
What people ask next
Does PSE's gas-to-heat-pump rebate let me keep the old furnace as back-up?
The archived page says old gas equipment must be removed or decommissioned, with "cut and cap" allowed. That points away from a keep-the-furnace setup, so confirm with the utility.
How much does a better furnace save on its own?
ENERGY STAR says northern units can be up to 18% more efficient than baseline and can save $160 a year. That's the agency's figure, not a Washington one.
Is an 80% furnace still legal to install after 2028?
The federal date is tied to when a furnace is made, per the rule's wording. Ask your contractor about stock made before December 18, 2028, rather than planning around it.
Decide next
Your furnace is fine but you have no AC: AC or heat pump?
- 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
Dual fuel or all electric: which heat pump setup fits your house?
- 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
Should you repair your furnace or AC, or replace it?
- Repair it
- Younger equipment, one clear fault, sound ducts
- Replace it
- Older equipment, repeat faults, or rooms that never felt right
Where this came from
- ENERGY STAR: Air-source heat pumps, checked November 3, 2026.
- ENERGY STAR: Heating and cooling, checked November 3, 2026.
- ENERGY STAR: Furnaces, checked November 3, 2026.
- PSE: Gas to heat pump rebate (archived copy, May 2026), checked November 3, 2026.
- PSE: Midstream discount (archived copy, June 2026), checked November 3, 2026.
- PSE: Detect a leak (archived copy, September 2026), checked November 3, 2026.
- Cascade Natural Gas: Emergency information (archived copy, December 2025), checked November 3, 2026.
- NW Natural: If you smell natural gas, checked November 3, 2026.
- Washington Supreme Court: Climate Solutions v. State, opinion (news-site copy), checked November 3, 2026.
- Cornell LII: 10 CFR 430.32, checked November 3, 2026.
- EIA: State residential energy prices, checked November 3, 2026.
- EIA: Washington residential natural gas, annual, checked November 3, 2026.
- EIA: Electric Power Monthly Table 5.6.A, checked November 3, 2026.
- CDC: Carbon monoxide, checked November 3, 2026.
- DOH: Carbon monoxide, checked November 3, 2026.
- Tacoma Power: Heat pump rebates, checked November 3, 2026.
- Washington Commerce: HEAR, checked November 3, 2026.
- L&I: Verify a contractor, checked November 3, 2026.
- King County: Residential mechanical permits, checked November 3, 2026.
- Seattle SDCI: Furnace and heat pump permit guide, checked November 3, 2026.