[cawthor]

Recently, we've been getting an intermittent vibration noise from our fridge / freezer. It sounds like a loud buzzing, maybe a fan vibrating. It can last for a couple of hours and then just stop. However, it always stops when you open either door and starts again when shut. I've heard it could be an evaporator fan, it sounds like it's coming from the top / back of the unit (but would this stop when the door is open?).

Any ideas are much appreciated.

[woodchuck]

Yes it should turn off with the door open to prevent air being blown out of the unit. It will also turn off when the thermostat turns the unit off and during the defrost cycle. The noise could be something blocking the fan (ice?) It could be going bad or be loose. See how to test it here.>>>Refrigerator Repair Guide: How To Test the Evaporator Fan - ACME HOW TO.com