Fellow RV'ers, this is my first post here, but an important one non the less. I have a feeling there are others out there like me that will do a google search and find this thread so I wanted to pass on some information I found while trouble shooting this problem.
As I was getting prepped for a trip this afternoon, I tripped the high temp limit switch while washing my coach. My 1st search brought me to this thread, and based on some of the information above, I ended up on another site, where a member posted detailed instructions on how to reset the switch. It can be done easily by the coach owner. I've pasted the instructions below. They were originally posted by "David-and-Cheryl" on Heartlandowners.org. A big thanks to them because within 10 minutes of reading their post, my fridge was back on-line...no trip to the dealer...no dealing with Norcold...I'm one day behind on my trip but planning on pulling out tomorrow morning. I hope this helps others...
1. Leave the refrigerator turned on.
2. Remove the lower refrigerator access compartment door on the outside of your RV.
3. Locate the black plastic recall kit box. Confirm that the red LED is lit and not flashing. (If it's not lit, or it's flashing, you have a different problem, so these instructions don't apply.)
4. If the recall kit box is not easily accessible, pull on it gently to remove it. It's held on by a simple spring clamp. Use caution as some of the wires leading to the box may be short, and you don't want to damage the circuit board by pulling on them too hard.
5. Slide your flat-blade screwdriver into each of the three clips that hold the box cover onto the base to open the clips. Lift the cover off the base. Do not detach any of the wires attached to the circuit board--the board needs to be powered to reset the switch.
6. Touch your hand and your magnet to the metal interior of the compartment to discharge any static electricity.
7. Locate the reed switch on the circuit board. It is directly above the LED. It looks like a small black rectangular component, about 1/2" long and 1/8" wide, and the circuit board says "SWITCH" next to it. Here's a photo, although your circuit board may look slightly different as there are different revisions of the recall kit.
8. Touch your magnet to the right end of the top of the reed switch and hold it there for about 5 seconds. (Avoid touching any other part of the circuit board.) This is the step I discovered by trial and error - simply moving the magnet around the switch won't do it; it takes prolonged contact at the right spot. When the switch resets, you may hear a faint click, and the red LED will go out.
9. Go inside the RV and verify that the refrigerator is on, has stopped beeping, and the front panel display shows no messages.
10. Wait 15-20 minutes to be sure that the refrigerator continues to operate normally. (I read some reports of the switch tripping again after a reset; this might be due to residual water remaining on the circuit board.)
11. Line up the three clips on the recall box base with the cover, and press the cover into place so that the clips snap shut.
12. Re-clamp the recall box in its original location. Ensure all the wires are firmly connected to the circuit board.
13. Replace the lower refrigerator access compartment door.