The listing says "heat pump." The photos show a beige box in the side yard with moss on the pad. Nobody at the open house knows how old it is, and the seller disclosure says "works fine."
That box is a four- to five-figure line item in your first five years of ownership, and it is one of the few major systems in a house you can evaluate in ten minutes with your phone. Here is exactly how to do it, what to ask, and what the numbers look like in the Puget Sound market in 2026.
Step one: read the data plate, not the listing
Every outdoor unit has a metal or foil data plate on the side of the cabinet. It is the single most useful document in the whole transaction.
What to photograph
- Model number and serial number. Most manufacturers encode manufacture date in the serial — commonly the first four digits as month and year, or week and year. Any HVAC contractor can date it from a clear photo in under a minute.
- Refrigerant type. You will see R-22, R-410A, or on brand-new equipment R-454B. R-410A is still available and serviceable. R-22 means the system is old enough that refrigerant cost alone can end a repair conversation.
- Tonnage. Usually visible in the model number. Useful later when someone tells you the system is "too small" — or too big.
- General condition. Rust streaks at the base pan, crushed or combed coil fins, a fan grille packed with fir needles, a unit buried in rhododendron. All of it tells a story.
Then go inside and photograph the air handler or furnace in the closet, garage, or crawlspace. Same deal — model, serial, and whether anyone has been changing the filter.
What age actually means in Western Washington
National lifespan averages are not our averages. A well-maintained heat pump here typically runs 15 to 20 years, because our climate is gentle on equipment. Winter design temperatures across our service area range from 17°F in Olympia and Lacey to 29°F in Tacoma and Gig Harbor. Summers are short. Compressors cycle less and work less hard than they do in Phoenix or Minneapolis.
So translate the age like this:
| Age of system | What it usually means for a buyer |
|---|---|
| Age of system0–8 years | What it usually means for a buyerLikely still under manufacturer parts warranty if it was registered. Verify, do not assume. |
| Age of system9–12 years | What it usually means for a buyerMid-life. Expect wear parts — capacitor, contactor, fan motor, defrost board. Budget, don't panic. |
| Age of system13–16 years | What it usually means for a buyerLate middle age. Get a dedicated HVAC evaluation before your contingency expires. |
| Age of system17+ years | What it usually means for a buyerPlan on replacement inside your first few years of ownership. |
One regional asterisk: if the home is in Des Moines, Burien, Normandy Park, Steilacoom, Gig Harbor, Fox Island, or anywhere else with a water view, salt air has been working on that coil the whole time. Coastal units age faster than their serial number suggests. Look hard at the fins and the cabinet seams.
What a home inspector will and will not tell you
A general home inspector is a generalist on purpose. On HVAC, a typical inspection confirms the system powers up, produces a temperature differential, and has no visible safety defect. Most inspectors will not run a heat pump in cooling mode when outdoor temperatures are below roughly 60°F, because it can damage the compressor. In a Puget Sound October, that rules out half the test.
What the inspection generally will not cover:
- Refrigerant charge and whether the system has a slow leak
- Actual capacity versus the home's heat loss, which takes a real load calculation
- Duct condition in the crawlspace beyond a visual glance
- Whether the installation was permitted
- Whether the defrost cycle works correctly
For anything over 10 years old, a separate HVAC evaluation is the cheapest insurance in the transaction. A technician can give you a condition read in under an hour. That is what a heat pump diagnostic and repair visit is built for, and the findings become leverage.
Seven questions to put in writing
Send these to the listing agent. Vague answers are themselves an answer.
- What year was the system installed, and by whom? An installer name means a service history exists somewhere.
- Do you have maintenance records? Annual service on a 14-year-old unit is a genuinely good sign.
- Has it been repaired in the last three seasons, and for what? Three repairs in two seasons is a pattern, not maintenance.
- Has refrigerant ever been added? Refrigerant is not consumed. If it was added, it leaked.
- Was a permit pulled for the installation? Washington's seller disclosure form asks directly about unpermitted work. Unpermitted HVAC can complicate an insurance claim later.
- Is there backup heat, and what kind? Electric strip heat, a gas furnace in a hybrid setup, or nothing at all changes your winter utility bills.
- Does the system cool as well as heat? Some older air handlers were paired with heat-only equipment or have a failed reversing valve that nobody noticed in July.
Red flags that justify a price conversation
- R-22 on the data plate. Not an emergency, but any significant repair is now a replacement discussion.
- A pad that has settled or tipped. Refrigerant lines and the compressor do not love being out of level.
- Ice buildup in winter beyond a normal 5 to 15 minute defrost cycle. A solid block of ice is a real problem.
- No ducts visible but a ducted system advertised. Verify what is actually there.
- Crushed flex duct in the crawlspace. Ductwork replacement runs $3,000 to $8,000 for a standard home.
- An outdoor unit three sizes larger than the house needs. Oversized systems short-cycle and wear out early.
What replacement actually costs here
Use real numbers when you negotiate, not round guesses.
| Scope | Standard markets | Affluent / luxury markets |
|---|---|---|
| ScopeHeat pump replacement on existing ducts | Standard markets$10,000 – $16,000 | Affluent / luxury markets$11,500 – $21,600 |
| ScopeNew ducted heat pump system | Standard markets$12,000 – $18,000 | Affluent / luxury markets$13,800 – $24,300 |
| ScopeDuctless mini-split | Standard markets$8,000 – $14,000 | Affluent / luxury markets$9,200 – $18,900 |
| ScopeTypical repair | Standard markets$150 – $1,500 | Affluent / luxury markets$175 – $2,000 |
Affluent markets include Seattle, Maple Valley, Normandy Park, Black Diamond, Steilacoom, and Fircrest. Luxury pricing applies in Bellevue, Gig Harbor, and Fox Island. Full detail lives in our Washington heat pump cost guide.
On rebates: local utility rebates may apply to a qualifying heat pump, and the amount depends on which utility bills the home for electricity, what is being replaced, and the efficiency of the equipment installed. Rebates follow the meter, not the county — two houses a mile apart can be on different programs. Programs change, so we confirm what your utility actually pays before quoting it and file the paperwork. The federal 25C tax credit ended December 31, 2025, so no 2026 installation qualifies for it.
How to use this at the closing table
The instinct is to demand the seller replace the system. That usually backfires. A seller on a deadline buys the cheapest available box from whoever can be there Thursday, and you own that decision for the next 15 years.
The better play is a credit based on a written contractor estimate. You keep control of the equipment tier, the sizing, the installer, and the warranty registration. A Varsity installation carries a 10-year parts and labor warranty in your name, and most installs are completed in one day — so you can schedule it for the week after you move in, with the house empty.
And be honest with yourself about urgency. A 14-year-old heat pump that heats the house, cools the house, and has service records is not a crisis. It is a known expense on a known timeline. That is a far better position than a "newer" system with no records and a leaking coil.
The buyer's version of our standard advice
If the system is under 10 years old and tests clean, enjoy it and set a maintenance reminder. If it is 12 to 15, get a technician out during the inspection period and price the replacement so you are negotiating with facts. If it is 17-plus or running R-22, assume you are buying a house plus a heat pump and plan the budget accordingly.
We do pre-purchase evaluations across King, Pierce, Thurston, and the edge of Kitsap County, with the seller's permission for access. You get a straight read on condition and a written proposal if replacement is the right call — no manufactured urgency, no pressure to decide before you have closed.
Call (253) 785-4622, Monday through Friday 8 to 6, or request an estimate online. Bring the photo of the data plate. It saves everyone twenty minutes.