Repair or replace? How we decide when an AC or furnace is done

The math we actually use

Multiply the age of the system in years by the cost of the repair. If the answer is over about 5,000, replacement usually wins. A 400 dollar capacitor on a 12-year-old unit is 4,800: fix it. A 2,200 dollar compressor on the same unit is 26,400: replace it. It is a rough rule, but it keeps people from pouring money into equipment that is about to fail somewhere else.

We also look at whether the system uses R-22 refrigerant, which was phased out and is now expensive to top off, and whether the repair is the second or third one in two years. Repeat failures mean the system is telling you something.

Repairs that are almost always worth it

Capacitors, contactors, fan motors, ignitors, flame sensors, thermostats, and drain problems. These are normal wear items on any system under fifteen years old. We carry them on the truck and most are done in one visit.

Repairs that usually are not

A failed compressor on a unit over ten years old, a cracked heat exchanger on any furnace (that is a carbon monoxide safety issue and the furnace should be replaced), a leaking evaporator coil on an R-22 system, or any major repair on a system that was undersized or poorly installed to begin with. Fixing one part of a bad installation does not fix the installation.

What a new system should include

A real load calculation of your home, not a guess based on the old unit. A look at the ductwork, because a new high-efficiency unit hooked to leaking ducts wastes the money you just spent. A written price before work starts. And a company that will still be in business, and still answering the phone, when the warranty matters. We have been in Washington since 2008.