AC \ Heatpump radiator corrosion
keeping the system clean is the number one thing a home owner can do. Things that will quickly kill your condenser coil are build up of grass trimmings, dust in the fins these hold moisture and rot out the aluminum fins, a simple rinse with a garden hose will flush the dust out and any salt if in a coastal area. The #1 killer of condenser coils I have seen is Dog pee, urin can destroy a coil in a very short time. Never use acid based cleaners, in fact home owners should not need strong cleaners if regularly hosed off. (Don't ever use a pressure washer this will fold the fins over and can ruin a coil). I flush my system monthly in the summer my daughter now lives in my last house and that unit is 18 years old and the coils look great. Any treatment you add to the coil may damage the factory coating if coated or possibly collect dust faster. Really a simple rinse is enough if regularly done to extend the life of the unit.