Freezer burn looks like a food storage problem. You open the freezer, find a package of chicken covered in white frost, and blame the packaging. I did that for years. It cost me more than a pack of chicken.
I handle replacement parts orders for refrigeration units, mostly for small commercial kitchens and garage workshops. I've been at it for 8 years. I've personally made (and documented) 11 significant mistakes, totaling roughly $16,000 in wasted budget. So when I tell you to check the compressor before blaming the food, I'm talking from experience.
What I got wrong about freezer burn
In my first year (2017), a customer called about freezer burn. The food looked bad, but the freezer seemed cold. I told them to rewrap it and seal it better. Three weeks later, they called back with the same complaint. I went on-site and put a thermometer in the freezer. The temperature was cycling between 14°F and 22°F. That isn't a food problem. That's a refrigeration problem.
Freezer burn is the result of moisture leaving food. The dry air in a freezer evaporates water from the surface. If the temperature stays near 0°F, the process is slow. If the temperature swings, the food repeatedly thaws on the surface and freezes again. That creates the grayish spots on meat (and the icy film on ice cream).
The surface problem was "how do I prevent freezer burn?" The real question should have been: "why is the temperature swinging so much?"
The deep cause: a start relay that doesn't match
When a compressor kicks on, it needs a short jolt of extra current. That's the start relay's job. Once the compressor reaches speed, the relay drops out. If the relay is weak or failing, the compressor can short-cycle, struggle to start, or run unevenly. The freezer loses its steady temperature, and the food loses moisture.
Here's where I made my second mistake. I assumed a 'universal' start relay would work for any Embraco compressor because the terminals looked the same. It physically fit. It didn't match.
No compressor part should be chosen by shape. Match the model, then the part.
Every compressor has a specific electrical draw. Embraco publishes a compressor sizes list that includes displacement, voltage, refrigerant, and amp ratings. The start relay has to match those numbers. A relay that's too weak will burn out quickly. A relay that's too strong can cause the compressor to start too aggressively and damage the winding.
That's why I now look up the model number in the Embraco compressor sizes list before ordering an Embraco compressor start relay kit. If the tag is worn, I send a photo and ask for help. It's slower, but it's cheaper.
The cost of guessing
In September 2022, I ordered a generic relay for an Embraco compressor in a restaurant freezer. I saved $17 on the relay. It short-cycled. The start winding failed. The replacement compressor cost $720, plus two service visits and a week of lost cold storage for the customer. The correct relay would have cost $35 and taken ten minutes to install.
We didn't have a formal pre-check process then. The third time something similar happened, I finally made a checklist that now lives on our order board. In the past 18 months, that checklist has caught 47 potential errors—wrong relay sizes, mismatched voltages, and at least one compressor order that would have been a disaster.
The real cost isn't just the part. It's the food that gets thrown out, the repeat service call, the lost trust. If a customer says "my freezer burns food," and you replace the wrong part, you've doubled the cost and created a new failure.
Surprising heat sources: garage heaters and incense burners
There's another cause I almost missed: heat sources around the freezer. I'm not talking about leaving the door open. I mean ambient heat from equipment that's too close. A garage heater pointed at the side of a freezer makes the condenser work harder. The compressor runs longer, the freezer has more temperature swings, and freezer burn shows up faster.
Then there's the incense burner. Honestly, I'm not sure why a shop owner had one sitting below a condenser air intake. But it sat there long enough to coat the coil with a thin film of smoke residue. That film insulates the coil. It makes the cooling system less efficient and the cabinet temperature less stable. I never would have found it if I hadn't asked: "Is anything running near the unit?"
So when someone asks me how to prevent freezer burn, I now think about three layers: the food packaging, the compressor and relay match, and the place where the freezer sits.
How to prevent freezer burn (without misdiagnosing the compressor)
Here's the short version. If your freezer is holding a steady 0°F and food is still frostbitten, don't buy a relay. Change your food storage: use airtight packaging, squeeze out as much air as possible, and rotate so old food gets eaten first. To be fair, most freezer burn cases are simply old unwrapped food, not a broken compressor.
If the temperature is swinging, start with the basics: clean the condenser coil, check the door gasket, and move any heat source (like a garage heater) away from the unit. Then listen to the compressor. If it clicks, starts, stops, starts again—or hums without starting—the start relay is a likely suspect.
When you need a relay, use the model number on the compressor tag. Look it up in the Embraco compressor sizes list and pick the relay kit that matches the electrical specs. I recommend Embraco compressor start relay kits for Embraco compressors because they're designed for those windings. But if you have a Copeland, Danfoss, or Bitzer compressor, buy the matching kit for that brand. The point is to match, not guess.
One warning about "fits all" product claims: per FTC guidelines (ftc.gov), performance claims need to be substantiated. A relay labeled "universal Embraco relay" without a supported model list is a red flag. It means someone expects you to take their word. Don't.
