What to check, in order
- Defrost it by hand
Empty it and leave it switched off with the doors open. Allow most of a day.
- Test the defrost sensor
And replace it if it has failed.
When to call an engineer
If you'd rather not test and replace the sensor yourself.
Quick answers
What does the E4 error code mean on a fridge or freezer?
The fridge can't run its defrost cycle properly, so ice builds up.
Can I fix E4 on a fridge or freezer myself?
Moderate (most of a day, mostly waiting). Start with: defrost it by hand; test the defrost sensor. If you'd rather not test and replace the sensor yourself.
Is E4 on a fridge or freezer worth repairing?
Worth fixing. Left alone, the ice eventually kills the cooling, and then you lose the food as well.
About this code
Unbranded and less common appliances don't publish one shared code list, so this page gives the most common meaning across makers. Your manual is the final word, and the model number that finds it is on a label inside the fridge, usually on a side wall, or on the back.
Last reviewed October 2026.