Norcold N611RT fridge AC heating element

I would test the element before doing anything.
Verify that there is 120 volts AC coming out of the circuit board.
Check the heating element for continuity.

I replaced mine on a 682 Norcold. It was rusted in pretty bad and I had to wiggle it back and forth with long needle nose pliers to remove it

I have never replaced one but here is a service manual and the ac heater part. It shows 2 fuses on the board. Fuse 3 is for the ac heater circuit. The trouble shooting guide starts on about page 15. It's probably indicating a problem in that circuit, not a failure of one particular component. Maybe it is, but it seems unlikely as there are multiple parts and reasons that the circuit could fail. Remove both ac and dc power before working on it.

Part

Manual