Choosing Heat & Airin Washington
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Should you repair your furnace or AC, or replace it?

Repair it or Replace it

Compared by the people who run this site. Updated . Rebates and prices checked November 3, 2026.

Whether to repair or replace comes down to age, the fault and your ducts, not age alone. ENERGY STAR's marks are more than 10 years for a heat pump or AC and more than 15 for a furnace or boiler. Those are prompts to evaluate, not a deadline to buy.

The verdict, by situation

  1. If your equipment is younger than those marks and has one clear fault

    Repair. Age gives you no reason to replace, so ask for the fault and part in writing.

  2. If your heat pump or AC is more than 10 years old and keeps failing

    Get a replacement bid next to the repair quote. That's ENERGY STAR's mark. If it's your AC, read AC or heat pump when the AC dies.

  3. If your furnace is more than 15 years old and needs a costly part

    Bid both. An ENERGY STAR furnace is "15% more efficient than a conventional furnace", and DOE's guide says a system over 15 years old can save by being replaced.

  4. If the equipment runs but some rooms stay cold or bills stay high

    Check ducts and air leaks before either choice. ENERGY STAR says these are "sometimes" the real sources of problems rather than your HVAC equipment. See seal or replace ducts.

  5. If your old electric furnace has failed and your utility pays for heat pumps

    Stop and read the rebate rules first. As of November 2026, Clark Public Utilities lists $1,000 for an electric furnace to central heat pump and Snohomish County PUD lists $1,800 for a ducted conversion. Both set conditions, so see rebate or wait.

A big square two-storey house with deep porches and a summer lawn in Walla Walla.
A big square two-storey house with deep porches and a summer lawn in Walla Walla.

Side by side

CompareRepairReplace
Age promptUnder 10 years (heat pump, AC); under 15 (furnace, boiler)Past those marks, and something else is wrong
Efficiency changeNone expectedENERGY STAR northern furnace: up to 18% better than baseline, can save $160 a year
SizingStays what it wasA new Manual J calculation
RebatesNone found for repairsDepends on utility and current heat
PermitsDepends on the workExpect them; WAC exemptions exclude replacing an equipment unit
RefrigerantEPA-certified technicianEPA-certified technician
Install qualityExisting setup staysPoor installation can cut efficiency up to 30 percent

Sources under the table: ENERGY STAR on replacing, ENERGY STAR furnaces, DOE consumer guide, WAC 296-46B-901, EPA Section 608, ENERGY STAR heating and cooling. No official formula compares a repair quote to a replacement bid, so use your own numbers and your own timeline.

What would change the answer

  • A written finding that the unit is unsafe. Ask what was found, how it was tested and whether it can be repaired, then consider a second opinion.
  • A planned move. A short horizon favors the repair, and Washington's CO alarm rule also applies at sale.
  • Federal furnace rules. Non-weatherized gas furnaces made on and after Dec. 18, 2028 must reach 95.0% AFUE, up from 80.0%, so the choice of units may change.
  • A rebate that needs its own contractor. PSE's electric-resistance offer needs a Trade Ally or Recommended Energy Professional and application within 30 days of purchase (archived copy, May 2026; confirm with the utility). A rushed swap can forfeit it.
  • A house that never felt comfortable. That hints at ducts or sizing, and a like-for-like replacement would repeat it.

What it costs, with dates

Repair quotes and replacement bids are the only price evidence you'll have, because no official source publishes an installed figure and this site won't invent one. Ask a repair quote to name the failed part, the labor and what it does not fix. Ask a replacement bid to itemize equipment and ratings, the Manual J calculation, ducts, electrical work, permits and removal.

Savings claims should be dated and checkable. As of November 2026, ENERGY STAR says northern furnaces can save $160 a year and oil ones about $90. No federal credit applies to anything placed in service after Dec. 31, 2025, per the IRS FAQ. For fuel comparisons if you're changing systems, use what heat costs.

Who does the work

Whoever you hire, look them up first on L&I's verify tool, which shows active registration, tradesperson certification and the workers' comp account. Registered specialty contractors carry a $15,000 bond. Permits vary by place: Tacoma lists like-for-like heat pump or furnace replacement as over the counter, and Seattle wants a refrigeration permit for any split system. Spokane's rules could not be confirmed, so ask the city. Details are on who pulls the permit.

Before a service call, you can check the breaker or switch and look at the filter. ENERGY STAR says to change it at least every 3 months. Leave gas valves, burners, flues, refrigerant and wiring to the technician.

What should you do first if you suspect a dangerous fault?

Get out of the house, then make the call. If a CO alarm sounds, everyone goes out first, then call 911 from outside, as DOH advises. CDC lists symptoms including headache, dizziness, upset stomach, chest pain and confusion.

If you smell gas, leave first. Don't use switches, plugs or a phone inside. Once outside and away, call 911 and your gas utility at its published number:

  • Puget Sound Energy: 1-888-225-5773 (archived copy, September 2026; confirm with the utility).
  • Avista: 800-227-9187 (archived copy, October 2025; confirm with the utility).
  • Cascade Natural Gas: 888-522-1130 (archived copy, December 2025; confirm with the utility).
  • NW Natural: 800-882-3377.
A round white carbon monoxide alarm resting on dark wood boards.
A round white carbon monoxide alarm resting on dark wood boards.

Why not just replace it with the same size?

Because the old size may have been wrong. DOE's guide warns that oversizing can cost too much, give poor comfort and lead to mold, and it says a contractor should use Manual J. If insulation or windows changed since the last install, the old number is even less useful.

Treat a bid with no load calculation as incomplete. Either way, your ductwork may need attention, since leaky ducts can pull particles from attics and crawl spaces into the house. New decisions by house type begin at the starting page.

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

Parts and examples

To see how a pro's service page lays out heating work, look at CentralPlumbingHVAC's heating page. It's a heating and cooling service company in Bucks and Montgomery Counties, Pennsylvania, not in Washington, and it shares an owner with this site. It's shown only as an example of how that work gets described.

What people ask next

How many years should a furnace last in Washington?

No source here gives a lifespan in years for Washington. ENERGY STAR's more-than-15 mark is its prompt to consider a replacement, and that doesn't mean your furnace is done at 16.

Should a contractor who says my furnace is unsafe also be the one selling the new one?

That's a fair reason to get a second opinion. Ask for the finding in writing, and check each contractor on L&I's tool. Don't relight or restart anything yourself.

Does replacing a working AC help a house that overheats?

Not if the ducts or air leaks are the real cause. ENERGY STAR says sealing and insulating ducts can improve efficiency by as much as 20 percent, so check those first.

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Where this came from

Start from your house