Your furnace quit on a wet 38-degree morning, a technician has the panel off, and the number he just said out loud is bigger than you expected. Now you have about ten minutes to decide whether to spend it or spend more.
There is a real answer to this, and it isn't "it depends." It depends on four things, and you can work through all four before the truck leaves your driveway.
The four questions that decide it
- How old is the furnace?
- What does this specific repair cost?
- Is this the first repair, or the third?
- Do you want air conditioning in the next five years?
Everything else — brand loyalty, the sunk cost of last year's repair, what the neighbor paid — is noise. Work these four in order.
Question 1: age
A gas furnace in Western Washington typically lasts 15 to 20 years. Our mild marine climate helps; a furnace here logs fewer run hours than the same box in Spokane or Bozeman, so it often outlives the national average.
Find the manufacture date on the data plate inside the burner compartment, or read it off the serial number — a technician can decode it in seconds.
- Under 10 years: repair, almost always. The rest of the machine has real life left.
- 10 to 15 years: repair if the number is reasonable. Start budgeting.
- 15 to 20 years: every four-figure repair is a replacement conversation.
- Over 20 years: you are maintaining a machine on borrowed time. Replace on the next real failure.
Question 2: the 50% rule
The cleanest test in the trade: if the repair costs more than half of a comparable new system, replace it.
Furnace replacement runs $4,000 to $8,000 installed in standard Washington markets and $5,000 to $10,000 in affluent markets or for high-efficiency condensing units in larger homes. Most furnace repairs land in the $150 to $1,500 range, a little higher in premium markets.
So for a typical home, the line sits somewhere around $2,000 to $3,000 in repair cost — and you should slide that line down for every year past fifteen the furnace has been running.
| Repair cost | Furnace age 8 years | Furnace age 18 years |
|---|---|---|
| Repair cost$250 | Furnace age 8 yearsRepair | Furnace age 18 yearsRepair |
| Repair cost$700 | Furnace age 8 yearsRepair | Furnace age 18 yearsRepair, but plan |
| Repair cost$1,400 | Furnace age 8 yearsRepair | Furnace age 18 yearsGet a replacement quote |
| Repair cost$2,500+ | Furnace age 8 yearsGet a replacement quote | Furnace age 18 yearsReplace |
Question 3: the repair history
One failed igniter on a twelve-year-old furnace is maintenance. Three service calls in two winters is a pattern, and the pattern is telling you the machine is wearing out in more than one place. Parts that fail together — inducer motor, then control board, then blower — are usually failing because the same underlying stress is on all of them.
Add up what you've spent in the last 24 months. If it's approaching a quarter of a new system and the furnace is over fifteen, you are financing a replacement in installments and getting none of the warranty.
Question 4: do you want cooling?
This is the question most homeowners skip, and it's the one that changes the math the most in 2026. More on that below.
Repairs that are almost always worth doing
These are cheap, common, and don't say anything bad about the rest of the furnace:
- Hot surface igniter. A consumable part. It cracks, it gets replaced, the furnace runs another decade.
- Flame sensor. Often just needs cleaning. Frequently the cheapest visit we run.
- Capacitor. Small part, big symptom.
- Pressure switch or blocked condensate line. Common in damp Puget Sound crawl spaces and garages.
- Thermostat or wiring fault. Not the furnace's fault at all.
If a technician quotes you a replacement on the back of one of these, get a second opinion.
Repairs that tip the scale toward replacement
- Cracked heat exchanger. This is a combustion safety shutdown, not a repair. On a furnace past ten years old, the part cost and labor get close enough to a new system that replacement is the honest recommendation almost every time.
- Failed blower motor or ECM module on a 15-plus-year-old unit — high part cost against a machine with little life left.
- Control board plus a second failure in the same visit.
- A furnace that was never sized right. If it short-cycles or has never heated the back bedrooms, repairing it just preserves the original mistake.
The 2026 wrinkle: price a heat pump before you sign
Here's where a lot of Washington homeowners leave money on the table. If your furnace is dead or dying and you also want air conditioning — which more Puget Sound homeowners want every summer — the comparison isn't repair versus furnace. It's three-way:
| Path | Standard-market installed cost | What you get |
|---|---|---|
| PathRepair the furnace | Standard-market installed cost$150 – $1,500 | What you getHeat, for now |
| PathReplace with a gas furnace | Standard-market installed cost$4,000 – $8,000 | What you getHeat only |
| PathReplace with a ducted heat pump | Standard-market installed cost$12,000 – $18,000 | What you getHeat and cooling in one system |
Adding standalone central AC later runs $5,000 to $12,000 on its own, so the furnace-plus-AC path often lands within a few thousand dollars of the heat pump path — and the heat pump is the only one of the three that can qualify for PSE's up-to-$4,400 in rebate money on a qualifying conversion.
Be clear on the rebate rules, because they changed: the federal 25C tax credit ended December 31, 2025, so no 2026 install qualifies for it. PSE rebate money is aimed at qualifying heat pump installations, not furnace-for-furnace swaps. Programs change — we confirm your current eligibility and handle the paperwork. And from April 2, 2026, PSE rebates require a PSE-certified installer. Varsity is one.
If you want the full side-by-side, we wrote it out in heat pump vs. gas furnace in Western Washington and should you replace your gas furnace with a heat pump.
When keeping the furnace is genuinely the right call
We say this out loud on estimates all the time, because it's true more often than the industry admits:
- The furnace is under twelve years old and the repair is a few hundred dollars.
- You're selling within two years. Buyers rarely pay a premium for new equipment.
- Your gas bills are low, you have no interest in AC, and the machine has never given you trouble.
- Cash is tight and the fix gets you through this winter safely. A safe, working furnace today beats a perfect plan you can't fund.
A hybrid setup is also worth asking about. If the furnace is young and healthy, a heat pump paired with it as backup keeps the gas equipment useful instead of throwing it away.
What an honest estimate should include
Before you decide, you should have, in writing: the specific failed part and what it costs, the furnace's age and remaining expected life, and a replacement price with equipment tiers — not one number on a napkin. We present Good, Better and Best options with the price attached to each, and every installation we do carries a 10-year parts and labor warranty. Most furnace replacements are finished in one day.
Want the ballpark before anyone comes out? The instant estimate tool gives you starting prices for a furnace, heat pump or mini-split in about 60 seconds. When you're ready for real numbers on your actual house, book a free in-home estimate — we measure, run the load calculation, and put the options in front of you without manufactured urgency.
The short version
Under fifteen years old with a repair under half the cost of new? Fix it. Past fifteen with a four-figure quote, or a heat exchanger crack at any age? Replace it. Want cooling too? Price the heat pump before you write the check — that's the decision that's worth the most money in 2026.
Call Varsity Heating and Cooling at (253) 785-4622, Monday through Friday 8 to 6, or request an estimate online. We serve 45 cities across King, Pierce, Thurston and Kitsap counties from our shop in Federal Way — and we'll tell you when the repair is the smarter buy.