E4 error code on a Defy Refrigerator is a indication that there is something wrong with the air movement inside the freezer compartment. (Older defy models has a red light blinking)
REASON for code
The freezer has made too much ice and is now all frozen-up or
it could be that freezer system is low on refrigerant (gas)
1. The freezer door wasn't closed proberly - just closed enough to switch off "door open" alarm and open enough to let moister in - resulting in over condensation on condenser.
2. Abnormal high open and closing of freezer door. In our part of the world (Port Elizabeth) the over icing often happens during summer because we have more humunity in the air during summer and the freezer are opened more frequently for treats.
4. Defrosting Element not heating - therefore not melting the ice - buildup
5. Pc control panel has gone on the blink
6. Refrigerant tubs has rusted causing a gas leak.
I hope the post has help you to make a more informed decision about your next step. Also read some of my previous post