The coils dump the heat the fridge pulls out of your food. When they are covered in dust, the heat has nowhere to go: the compressor runs longer, the fridge runs hotter, and the electricity bill climbs. Cleaning the coils is a twenty-minute job with a vacuum, and it is the single most effective maintenance a fridge ever gets.
On older fridges the coils are a black grid on the back. On newer ones they sit underneath, behind the kick plate at the bottom front. Check the manual if you are not sure — the location decides whether you pull the fridge out or take the kick plate off. Either way, unplug the fridge first.
Unplug it. Pull the plug before you touch anything. The coils sit next to the compressor and the fan, and neither should run while your hands are in there.
Pull it out. Empty the top of the fridge, lay a towel on the floor to protect it, and pull the fridge straight out. Do not kink the water line if the fridge has an ice maker — a kinked line leaks.
Find the coils. Look for the black grid on the back or underneath behind the kick plate. The kick plate usually pulls off with a gentle tug or two screws. The coils are the dusty part — you will know them when you see them.
Vacuum them. Vacuum the coils with a brush attachment, top to bottom, gentle and slow. Do not bend the fins — bent fins block the airflow and the coils cannot dump heat. A coil brush reaches between the coils where the vacuum cannot.
Wipe the fan and the drip pan. Wipe the fan blades and the drip pan underneath with a damp cloth. The drip pan collects condensation, and mold in the pan is the smell people blame on the food.
Push it back and plug in. Push the fridge back, leaving an inch of space behind it for airflow, level it with the feet, and plug it in. Listen for the compressor: it should cycle on and off, not run nonstop.
Clean coils fix the most common cause, but not every cause. Test the door seal: close the door on a dollar bill — if it slides out easily, the seal is worn and warm air leaks in. Check the thermostat setting: the fridge should be 37–40°F, the freezer 0°F. And check that nothing blocks the vents inside. The fridge runs all the time guide covers all six causes, from dusty coils to a tired compressor.
Twice a year, or every three months if you have pets — pet hair is the fastest way to clog a set of coils. Clean them after a renovation too: construction dust finds the coils within days. A fridge that is not cold enough is often a fridge with dirty coils — the fridge not cold enough guide starts with the same check. And a leak inside the fridge is usually the defrost drain, not the coils — the fridge leaking inside guide covers that fix.
Twice a year, or every three months if you have pets. Dusty coils make the compressor run longer and hotter, and a hot compressor fails years early.
No — vacuum and wipe only. Water on the coils and the electrical parts around them is a bad idea. A damp cloth on the fan and the drip pan is fine; the coils themselves get the vacuum.
Most often dusty coils, a worn door seal, or a thermostat set too cold. Clean the coils first — it is the cheapest fix and the most common cause.
Take the kick plate off — it usually pulls off or unscrews — and use a long coil brush or a vacuum with a crevice tool. If you still cannot reach them, a refrigerator technician cleans them as part of a service visit.