How often should you clean refrigerator coils?

Short answer

Clean the refrigerator coils every 6 to 12 months. With pets that shed, every 3 months. The coils are the black grid on the back of the fridge, or on newer models a coil hidden behind the kick plate at the bottom, and they're where the fridge gets rid of the heat it pulls out of the food. A vacuum and a long, thin coil brush clear them in 15 to 30 minutes, and the brush costs $0 to $15.

Why it matters

A refrigerator is a heat pump. It moves heat from inside the box to the coils outside it, and the coils hand that heat to the air in the kitchen. That only works if air can reach the coils. A felt of dust and pet hair wrapped around them is a blanket, and the heat stays in the refrigerant.

The compressor runs longer to make up for it. The sides of the fridge get warm. The electric bill creeps up, because a fridge runs all day and all night, so a little extra on every cycle adds up more than for any other appliance. And the compressor, which is the part that decides whether a fridge lasts its full 10 to 15 years, spends those years running hot. A compressor that fails on an older fridge usually means a new fridge, at $1,000 to $3,000. A coil brush is the cheapest part of that whole equation.

When to do it more often

Pets that shed: every 3 months. Fur is drawn to the coils by the fan and mats on them far faster than dust does.
A fridge in a garage or a dusty workshop: every 3 months, for the same reason.
A kitchen where the fridge sits next to the stove: cooking grease in the air makes the dust stick, so lean toward the short end of the range.

What you need

A coil brush, the long flexible bottle-brush shape that reaches under and between the coils
A vacuum with a crevice tool
A screwdriver, for a kick plate held on with screws

Steps at a glance

Unplug the fridge, or switch off its breaker.
For back-mounted coils, pull the fridge away from the wall. For bottom coils, pull off the kick plate at the front.
Work the coil brush along the coils in the direction they run, to pull the fur and dust loose.
Vacuum up what the brush frees, using the crevice tool to reach between the coils and around the fan.
Repeat the brush and vacuum until the coils look like metal again.
Vacuum the floor under the fridge, replace the kick plate, push the fridge back, and plug it in.

You're done when the coils are bare metal, the fan spins freely, and the fridge starts up and runs.

Signs it's overdue

The fridge runs almost constantly, with the hum rarely stopping.
The sides of the cabinet feel warm to the touch.
A visible mat of dust on the coils when you look behind the kick plate or the back.
Higher energy bills without another explanation.

DIY or pro

This is an easy job. The whole trick is the brush: a vacuum alone can't reach between the coils, and the long bristles of a coil brush are made for the gap. Pulling a fridge out from the wall is the hardest part, and sliding it onto a towel or a piece of cardboard makes that easier on the floor.

An appliance technician's service call runs $75 to $150, and cleaning the coils is one of the first things a technician does on a fridge that's running warm. If you've cleaned them and the fridge still runs constantly or won't hold temperature, that's the call to make, because the problem is in the refrigerant or the compressor.

Safety

Electricity: unplug the fridge before you put a brush or a vacuum nozzle anywhere near the coils, the fan or the compressor. The condenser fan can start without warning when the fridge is powered, and the compressor's terminals carry house voltage.

FAQ

Where are the refrigerator coils?

On older fridges, the black grid on the back. On most newer ones, a coil tucked behind the kick plate at the bottom front, with a fan beside it.

Does cleaning refrigerator coils save energy?

Yes. Clean coils shed heat easily, so the compressor runs less. A fridge runs around the clock, so even a small saving per cycle adds up.

Can I use a regular vacuum on the coils?

Only for what a brush has already loosened. The coils are too close together for a vacuum nozzle to reach between them, which is what the coil brush is for.

How do I know the coils are dirty?

Look. If they're furry or gray instead of black metal, they need cleaning. A fridge that runs almost without stopping is the other sign.