A refrigerant leak from your AC coil is one of the most common — and preventable — causes of system failure. Here's what causes them and what you can do.
Refrigerant leaks are one of the most frustrating AC problems homeowners face. Unlike a failed capacitor or a worn belt — problems with clear mechanical causes — refrigerant leaks can be subtle, develop slowly, and be difficult to locate. Here's what you need to know.
How Refrigerant Leaks Develop
The most common cause of refrigerant leaks in residential AC systems is a phenomenon called formicary corrosion — a type of pitting corrosion that affects copper coils. It's caused by the reaction of copper with formaldehyde and other VOCs (volatile organic compounds) that are common in modern homes (from furniture, carpets, cleaning products, and building materials). The reaction creates tiny pinholes in the copper tubing that allow refrigerant to escape slowly.
Other causes include:
- Physical damage to the coil from debris or improper handling during installation
- Vibration over time loosening fittings and connections
- Factory defects (less common but not rare)
- Age-related metal fatigue
Signs of a Refrigerant Leak
- Reduced cooling performance — the system runs but doesn't cool as effectively
- Ice forming on the refrigerant lines or evaporator coil
- Higher electricity bills (the system runs longer to compensate)
- Hissing or bubbling sounds near the indoor or outdoor unit
- Warm air from supply vents despite the system running
Why "Just Recharging" Isn't the Answer
Adding refrigerant without finding and fixing the leak is like adding oil to an engine with a leak — it buys time but doesn't solve the problem. The EPA requires that refrigerant leaks be repaired before recharging a system. Beyond the legal requirement, continuing to operate a system with a leak damages the compressor and wastes money on refrigerant that will just leak out again.
Prevention
The most effective prevention is regular maintenance. During a tune-up, our technicians check refrigerant levels and inspect coils for early signs of corrosion. Catching a small leak early — before the refrigerant level drops significantly — prevents compressor damage and keeps repair costs manageable.
Call On Time Home Services at (951) 277-6895 if you suspect a refrigerant leak. Our AC repair technicians serve Temecula, Murrieta, and all of Southern California.
