How to Clean Your Furnace’s Evaporator Coil

As cooler weather approaches, you probably ask a lot of from your heating system — warm and comfortable home, clean air and reasonable heating bills. For your furnace to deliver the goods, it needs a little help in the form of regular cleaning. Read on to learn why it’s important to clean your evaporator coil, and how to do.

What’s an Evaporator Coil?

The evaporator coil is the heat exchanger component of your heat pump or central A/C. It transfers heat energy into your home (heat mode) or out of your home (cool mode). No matter the season, however, the evaporator is highly susceptible to collecting large amounts of dust, dirt and even mold growth.

Further, if you heat your home with a gas furnace and cool with a central A/C system, your A/C’s evaporator coil probably sits atop the furnace and shares the blower. So, a dirty coil — even if only used for cooling — is going to obstruct airflow and heating efficiency.

Evaporator Coil Cleaning 101

The first step to cleaning your evaporator is safety. Turn off the furnace at the thermostat, circuit breaker and furnace disconnect switch. Next:

• Remove the blower compartment panel.
• Remove the panel to the evaporator.
• Use soft cleaning towels to hand-clean the coil.
• Use a soft brush to very gently clean the fins (they bend easily).
• Wipe clean the blower compartment, fan and assembly.
• Wipe clean the condensate pan.
• Pour one quart of a 50/50 bleach and water mixture into the pan to kill micro-organisms in the system.
• Reattach the panels and turn on the furnace power.
• Change or clean your air filter.

Alternatively, spray the entire coil and fins with an antimicrobial coil cleaner. A foaming, self-rinsing spray cleaner is the easiest. Better yet, ask your HVAC professional to clean the evaporator for you during your upcoming preventive maintenance appointment!