Noisy Refrigerator

Our refrigerator (dometic) gets suddenly loud every once in a while with a whirring/humming noise. It has been doing this the entire two years we have had it. The noise comes when the fridge is trying to 'defrost' the fins in the rear. It occurs more frequently in humid climates on warm days. It rarely occurs in cool, dry climates.
Check the fridge fins for ice. The greater the ice build up the more frequently the fridge will make the noise. We just had to defrost ours.

The convertor might be close to the reefer, if so they have a fan to cool them down and sometimes get confused with the reefer and other items in the unit..

Chris is correct. If you have a slide out kitchen, your refrig has a cooling fan on the back side that kicks on when the temps are high on the coils. Mine is very noisey and runs for quite a while, especially if it's a warm day. When camping and it's hot, I sometimes remove the black plastic vent cover on the outside of the slide out to let out some of the hot air and it seems to help. I have read that there are replacement 12V computer fans that are quite a bit quieter so I'm going to order one and give it a try. Mine is very accessible and easy to replace.

If it's in a slide, it has fans on the back. If the noise is objectionable, you may be able to have them swapped for larger but quieter fans, but they need to be there.

Not sure what size or make fridge it is but our new Montana has the 18 cu ft Dometic (largest RV fridge currently made) and this thing has 4 or 5 fans that cycle on inside and outside. You can hear them clearly when they kick on. You can tell when it's on gas also because the burner sounds like a blow torch.

RV fridges have no moving parts so no noise.........except for any fans in outside compartment
So if you are hearing noises.......remove vent cover and investigate.


As for whether electric is ON

While you have that vent cover off investigating noise touch the electric element/stack area

CAUTION: IT will be HOT ---300*F PLUS

I would think a good way to make sure it's running on electricity is to just turn off the gas for a bit.

I bet you lost the axial fan in the back. You can find the wires and unhook it and see if the noise goes away.