Ways to Ensure You're Preventing HVAC Coil CorrosionEffectively preventing coil corrosion can help avoid early replacement of these critical and expensive components. Both the air conditioner indoor evaporator coil and outdoor condenser coil circulate air through coil passageways. Chemical pollutants in the air combined with condensation or high humidity form corrosive acids that cause pinhole refrigerant leaks in copper tubing incorporated in the coil. These leaks are generally not repairable and, in many cases, installing an entirely new air conditioner is less expensive than replacing both coils.

Preventing HVAC Coil Corrosion

Cleaning A/C coils not only helps avoids substantial replacement expenses, it also sustains optimum system cooling performance and efficiency. The indoor evaporator coil is sealed inside the system air handler and not very accessible for the average do-it-yourselfer. However, scheduling regular annual preventive maintenance by a HVAC service technician will include coil cleaning procedures with solutions formulated to neutralize corrosives. The same procedure will be performed on the outdoor condenser coil.

To supplement annual professional coil cleaning with a simple DIY procedure, the outdoor condenser coil may be opened up and flushed with water from a garden hose twice a year to clean and remove corrosive acids.

  • Turn off electrical power to the outdoor unit at the main power switch, typically mounted on the wall of the house next to the unit.
  • Using a screwdriver or nutdriver, remove screws that secure the side panels of the condenser coil. Lift off the top of the unit that includes the fan.
  • First spray water from the inside of the unit directed through the coil fins and tubes towards the outside. Then spray from the outside, directing spray inwards through the fins and tubes.
  • Let the unit air dry completely, then reinstall side panels and top fan unit in the reverse order of removal. Restore electrical power at the main switch.

For annual professional service that includes preventing coil corrosion, contact Mowery Heating, Cooling and Plumbing.

Our goal is to help educate our customers in Brownsburg, Indiana and surrounding areas about energy and home comfort issues (specific to HVAC systems).