Dealing With an Iced-Up Evaporator

Heavy frost buildup on the evaporator coils is a common reason why a fridge stops cooling properly. In this case, the defrost system isn’t doing its job, which forces the unit to work twice as hard without actually dropping the temperature. We used a steamer to carefully clear out the ice and then tested the defrost heater and thermostat to find the root cause. Getting the airflow back to normal is much more cost-effective than letting the compressor burn out from the extra strain.

What the customer reported

This Surrey job is about a refrigerator that had stopped cooling properly. The record doesn’t give the temperature, the make or how long the problem had been going on, so we’re keeping to the general picture: heavy frost on the evaporator coils, and a fridge that wasn’t dropping the temperature the way it should.

Heavy frost on the evaporator is a common reason why a fridge stops cooling. That’s why finding the cause matters.

What the diagnosis found

The write-up says the defrost system wasn’t doing its job. When that happens, frost builds up on the coils and the unit has to work twice as hard without actually lowering the temperature. The ice acts like a blanket over the coils, and the cold air that should reach the food compartment doesn’t get through properly.

Seeing ice on the coils tells you what’s happening, not why. To find the root cause, our technician tested the defrost heater and the thermostat.

The part and the repair

The record doesn’t name a part that was fitted, so we’re not going to claim one. What it does describe is the work. The technician used a steamer to carefully clear out the ice, then tested the defrost heater and the thermostat to find the root cause.

Using a steamer is a gentle way to melt ice off the coils without hacking at it, and the word carefully matters here, because evaporator coils are thin and can be damaged. The record doesn’t state the test results, so we can’t say which component was at fault in this case.

How a fridge defrost system works

In general, a frost-free refrigerator has a defrost heater that warms the evaporator coils now and then to melt away frost, and a thermostat or sensor that helps control when that happens. Where the design uses these parts, a failure in the heater, the thermostat or the control can leave the coils to ice over. The exact setup varies by brand and model. The airflow is what suffers first, because the fan has to push air through coils that are packed with ice.

How to avoid this fault

Leave a little space around the food so cold air can circulate, and don’t let the door sit open. Clean the door gaskets now and then so they seal properly.

Why it matters

A fridge fighting a frozen evaporator is working hard for no result. If yours is warm and the back of the freezer section is iced over, ASAP Appliance Repair in Surrey can find out why.