When to repair your AC and when to replace it

The short answer

Repair it if it is under twelve years old, still uses a refrigerant you can buy, and the repair costs less than about a third of a new system. Replace it if two or more of those are false.

That rule gets the decision right most of the time. The rest of this explains where it breaks, because the cases where it breaks are the expensive ones.

Age is the first filter, and twelve is the number

Air conditioners and heat pumps in this climate work harder than the same equipment does further north. A Triangle summer runs a compressor for months, and our winters are mild enough that a heat pump barely rests either. Fifteen to twenty years is the honest lifespan of a well maintained system here, and ten to fifteen for one that has never been serviced.

The reason twelve matters is not that something breaks on the twelfth birthday. It is that repairs start clustering. A system that needs one part at twelve will usually need another within two seasons, and each of those visits carries a diagnostic fee of $89 on top of the part. Two or three of those in three summers costs more than a share of a new system and leaves you with an old one.

If your system is under ten, repair it. Almost always. Under ten, the parts are available, the efficiency gap to a new unit is small, and the remaining life is long enough to be worth the money.

The refrigerant question is the one most people have not heard about

Systems installed before roughly 2010 use R-22. It has not been produced or imported since 2020. The only R-22 left is reclaimed, and it costs several times what R-410A costs.

That changes the arithmetic completely. On an R-22 system a refrigerant leak is not a cheap repair, it is a recurring bill, because a leak that has been topped up once will be topped up again. We will still do it. We will also tell you plainly that you are buying time rather than fixing something, and roughly how much time.

Newer systems are moving to R-454B and similar low-global-warming refrigerants. That transition does not affect an R-410A system you already own, and anyone telling you your R-410A unit is about to become unserviceable is selling you something.

Compare the repair to a third of a replacement

The common rule of thumb multiplies the repair cost by the age of the system and compares it to the replacement cost. It is a reasonable heuristic and it is too clever to remember at the kitchen table with a technician standing there.

Use a third. If the repair costs more than about a third of what a new system costs, and the system is past ten, you are putting good money into a bad asset. Our HVAC work runs from $180 to $12,000 across everything from a capacitor to a full changeout, and the specific band for your job is on the AC repair and AC installation pages.

Ask for both numbers on the same visit. Any contractor who will quote a repair but not a replacement, or the reverse, is choosing for you.

The compressor usually ends the argument

A failed compressor on a system past ten years old is the point where almost everyone should replace.

The part is the single most expensive component in the system, the labour to change it is significant, and a compressor rarely fails for no reason. It fails because something else has been wrong for a while: low refrigerant charge from a leak, a restricted metering device, poor airflow from a dirty coil or a collapsed duct. Replace the compressor without finding that cause and you have bought a very expensive part that will fail again.

The exception is a compressor still inside its manufacturer warranty, which is common on systems under ten. Then you pay labour and refrigerant rather than the part, and repair usually wins.

Efficiency is real, but the sticker is not the saving

A modern system will use meaningfully less electricity than a 2005 one. It will not use half.

The efficiency rating on the box is measured under test conditions, and the gap between that and your house depends on duct leakage, insulation, and whether the equipment is correctly sized. We have replaced fourteen year old systems and delivered a large improvement, and we have replaced fourteen year old systems in houses with leaking attic ducts and delivered very little, because the new equipment was pushing conditioned air into an attic exactly like the old one did.

If someone offers you a saving figure without asking about your ductwork, they are guessing. Our duct work page explains why that is often the better place to spend the first few thousand dollars.

Sizing matters more than the rating

The most common defect we find in Triangle houses is equipment that is too big.

Oversized equipment cools the air quickly, satisfies the thermostat, and shuts off before it has removed the humidity. You end up with a house that reads seventy two on the thermostat and feels clammy, and with equipment that short cycles itself to an early death.

If you are replacing, insist on a load calculation rather than a match to what is there. Replacing like for like just inherits whoever's mistake it was in 1998.

When repair is clearly right

• The system is under ten years old.
• It uses R-410A or newer.
• The fault is a capacitor, a contactor, a fan motor, a control board or a thermostat.
• It has been serviced, and this is the first significant failure.

When replacement is clearly right

• The system is past fifteen.
• It uses R-22 and has a refrigerant leak.
• The compressor or the evaporator coil has failed and the warranty has expired.
• You are already paying for repairs most summers.
• The house has never been comfortable, in which case the sizing was probably wrong from the start and replacement is the only chance to fix it.

What we do on the visit

We diagnose the actual fault, tell you the repair price before touching anything, and if the system is old enough for the question to be live we give you the replacement figure at the same visit. The diagnostic fee is waived if you approve the repair.

We do not sell replacements from a photograph or a phone call, and we do not quote a replacement without a load calculation. If the answer is that your fifteen year old unit has another three summers in it, that is what you will be told.

The cheapest version of this whole decision is not having to make it in July. Maintenance in spring finds the failing capacitor before it strands you, and it is the only part of this article that saves money rather than spending it.