Should you repair or replace your evaporator coil?
Updated August 2026
← Every repair-or-replace call
Replace just the evaporator coil if the system is under 8 years or still in warranty; on a system past 10 years a leaking coil usually means it is time for a full changeout. The coil as a standalone part runs $900–1,800 to replace, but on an older system the outdoor condenser and indoor coil are a matched, aging pair, and a new coil bolted to a tired condenser is often false economy. A full changeout runs $5,000–9,000. If the system uses R-22, a coil leak almost always tips the decision to replace the whole system.
The short version
An evaporator coil leak forces a coil-versus-system question. Under 8 years, or with a warranty still covering the part, replace the coil alone, because the rest of the system has years left and $900–1,800 is far below a changeout. Once the system passes 10 years the calculus changes, since pairing a fresh coil with a decade-old condenser and compressor leaves you a mismatched, inefficient system that may need the condenser next. Refrigerant type is the accelerant. An R-22 coil leak means recharging a phased-out refrigerant that now runs $100-plus per pound, so on those systems the leak is usually the cue to replace everything and move to modern refrigerant.
Your situation, decided
| Situation | Verdict | Why |
|---|---|---|
| Under 8 years or coil still under warranty | Repair (coil only) | A $900–1,800 part on a system with years left |
| Coil leaking, system past 10 years | Replace system | A new coil on an aging condenser is false economy |
| R-22 system, coil leaking | Replace system | Recharging phased-out refrigerant at $100+/lb is a dead end |
| Coil frozen but not leaking, airflow or charge issue | Repair | Fix airflow or refrigerant; the coil itself is fine |
| Formicary pinhole leaks at 8–10 years | Judgment call | Weigh the $900–1,800 coil against a $5,000–9,000 changeout |
What each path costs
Repairs typically run $900–1,800; a replacement is $5,000–9,000 installed. An evaporator coil lasts 10–15 years. Replace it alone under 8 years; past 10 the coil and condenser are an aging pair, so a full changeout is smarter. Price your own number on the home maintenance cost calculator before you commit either way.
The repair-or-replace call is easy when you know the unit's age and service history. OnOtto keeps both, plus the maintenance that delays this decision for years.
Start your home's service log, freeFrequently asked questions
Can a leaking evaporator coil be sealed instead of replaced?
Sometimes, but treat it as a stopgap. Injectable leak sealers exist and can buy a season on a small pinhole, yet most HVAC pros consider them a temporary measure, not a fix, and some manufacturers void warranties over them. If the coil is under warranty, replace the part properly for $900–1,800. If the system is old and you are nursing it to the end of a season before a planned changeout, a sealer may be a reasonable bridge. It is not a substitute for replacing a coil that keeps leaking.
Why do evaporator coils leak in the first place?
Usually corrosion, not age alone. Formicary corrosion from indoor air pollutants eats microscopic pinholes in the copper, and it can strike coils well before the metal wears out. Vibration and factory defects account for the rest. Keeping the coil clean helps airflow but does not stop corrosion, though a clean coil and a correct charge prevent the freezing that stresses it. If your coil leaks under 8 years, check whether it is a known warranty issue before paying out of pocket.
What happens if I just keep recharging the refrigerant?
You pay repeatedly and risk the compressor. Refrigerant does not get used up; if it is low, it is leaking, and topping off a leaking coil means buying refrigerant again and again, especially painful with R-22 at $100-plus per pound. Worse, a low charge makes the coil freeze and the compressor run hot, which can trigger a far bigger failure. Letting the coil freeze over and over carries its own costs. Fix the leak or replace the coil rather than feeding it refrigerant.