The garage refrigerator, and what a San Diego September does to it

Half the households in this county keep a second refrigerator in the garage, and it is almost always the older one that got displaced by a kitchen remodel. It works fine for years, and then in the back half of September it starts running without stopping, or the freezer goes soft, and it looks like the compressor is dying. Usually it is not.

A refrigerator does not make cold

It moves heat from the inside to the outside. That is the whole machine. Which means its ability to keep your food at 37°F depends entirely on having somewhere cooler to put the heat — and an uninsulated garage behind a west-facing door in September is not that place. An attached garage in an inland part of the county can sit above 105°F through the afternoon, and it stays hot long after sunset because the slab and the walls have been charging all day.

Most domestic refrigerators are rated to work in ambient temperatures up to somewhere around 100 to 110°F, and that rating assumes clean airflow across the condenser. Take the machine past its rating and nothing dramatic happens — it simply runs continuously, never reaches setpoint, and the compressor spends the summer at a duty cycle it was not designed for. That is what shortens its life, not one hot day.

The two-minute check

• Look at the condenser coils. On an older unit they are the black grille on the back; on most units since the 1990s they are underneath, behind a snap-off grille at the floor. In a garage they will be carpeted in dust, and dust is insulation on the one surface whose entire job is to shed heat. Unplug it, vacuum them, and put the grille back.
• Check the clearance. Three or four inches at the back and sides, and nothing stacked on top. A refrigerator pushed flat against drywall with boxes on the lid has nowhere to dump heat.
• Put a thermometer in the garage, not in the fridge. If the room is above 100°F in the afternoon, you have found your fault and no part will fix it.
• Check the door seal with a dollar bill. Close it on the bill and pull — if it slides out with no drag, the gasket has gone hard, and in a hot garage a weak seal costs far more than it does in an air-conditioned kitchen.

The thing that guarantees a failure: putting the garage fridge in the corner furthest from the door, against two exterior walls, with the condenser facing the wall. It is the natural place to put it and it is the worst one available.

The winter half of the same problem

It is worth knowing about even here, where it is milder. Many older refrigerators have a single thermostat, and it sits in the fresh-food compartment. In a cold garage that sensor reads a temperature it is happy with, so it stops calling for cooling — and the freezer, which shares the same compressor, thaws. People discover this in January with a freezer full of ruined meat and conclude the appliance failed. It did exactly what it was designed to do, in a place it was not designed for.

Some manufacturers sell a garage kit for this, which is essentially a small heater that fools the thermostat. If you are buying a unit specifically to live in a garage, buy one rated for it rather than retrofitting the problem.

When it is actually broken

If the coils are clean, the clearance is right, the seal drags on a dollar bill, and the garage is not an oven — and it still runs constantly or will not hold temperature — then something has failed, and the usual suspects are a condenser fan motor, a defrost system that has stopped defrosting, or a sealed-system fault. The first two are ordinary repairs. The third needs EPA certification to open, which this company does not hold, so we diagnose it, tell you plainly what it is, and you are not charged for work nobody here can do.

Before you call, the refrigerator troubleshooting guide walks the same checks a technician does first.