The outdoor cooling unit, a central air conditioner or a heat pump. Like any major system it has a service life, and replacing one is a four- to five-figure cost most listings never mention.
$4,500 to $9,000 for central AC (condenser-only $3,500 to $6,500); high-efficiency $6,000 to $12,000Address soonHeating
The quick answer
Central AC lasts about 10 to 15 years (heat pumps 10 to 16); past that, efficiency drops and a failure can come any summer, and older units may use the phased-out R-22 refrigerant that's costly to top up. Replacing central AC runs about $4,500 to $9,000 and a heat pump $8,000 to $20,000 (often with rebates). Read the date on the outdoor unit's nameplate and factor a near-term replacement into your offer.
You are reading the aging air conditioner & heat pump page. Type the year the house was built and I will tell you what else tends to be true at that age, what it costs, and what to ask. One number, ten seconds.
Free. No account. Educational and impartial, not a home inspection.
Why it matters
Central AC typically lasts about 10 to 15 years, and heat pumps 10 to 16; past that, efficiency drops and a failure can come any summer. An older unit often uses the phased-out R-22 refrigerant, which is expensive to top up. Knowing the age lets you budget and negotiate, and if you plan to add a heat pump, it flags whether the electrical service can support it.
How to spot it
Read the manufacture date on the nameplate of the outdoor unit (often encoded in the serial number, or on a separate date sticker). Look for rust, a bent or dirty coil, and the refrigerant type. A unit that is loud, iced-up, or short-cycling is near the end of its life.
What it costs
Ontario installed pricing: replacing central AC runs $4,500 to $9,000 (high-efficiency $6,000 to $12,000; condenser-only swap $3,500 to $6,500). A cold-climate heat pump, which replaces the AC and most of the furnace's work, runs $8,000 to $20,000 before rebates, with Ontario rebates currently up to $7,500.
What to do
Note the age and factor a near-term replacement into your offer if the unit is aging. If you want a heat pump, confirm the electrical service and ducting suit it, and check current rebate programs before you budget.
Education and triage, not a home inspection. Casaroo reads the age and condition clues from your photos, an HVAC technician confirms the remaining life. We flag; we don't inspect.
Common questions
Is an old air conditioner worth negotiating over?
Yes, and it is one of the easier asks because the age is documented on the nameplate rather than a matter of opinion. A unit past ten years is a known upcoming cost of $4,500 to $9,000, and a seller who will not move on price will sometimes agree to a credit instead.
Can I just replace the outdoor unit and keep the rest?
Sometimes. A condenser-only swap is cheaper than a full system, but if the indoor coil is the original match for an R-22 unit, an HVAC contractor will often push you to replace both so the system is matched and uses current refrigerant.
Should I replace an aging AC with a heat pump instead?
It is worth pricing, because a cold-climate heat pump does the cooling and most of the heating for $8,000 to $20,000 before rebates, and Ontario rebates can take a large bite out of that. Ask an HVAC contractor whether your electrical service and ducts can support one before you budget.
Will a general walkthrough check the air conditioner?
A general walkthrough will note the age and run it if the weather allows, but they will not open the system or measure refrigerant charge. If the unit is old or you suspect a problem, an HVAC technician is the person who can tell you what is really left in it.
Costs and rebates are 2026 estimates that change. Confirm current programs and get a licensed HVAC quote.
Last reviewed 2026-07-10.
This guide is general education, not a home inspection and not advice for your specific property. Always
consult the appropriate licensed professional, and get a licensed home inspection before you remove conditions
or buy. Cost ranges are 2026 estimates that vary by region, size, and access; confirm specifics with a
qualified professional.