The best solution to this problem- something the OEM's *should* put in, IMHO, is the
ARP refrigerator control, which monitors boiler temperature and reacts quickly to prevent overheating. You will find a bunch of data on that site about the issue.
There are 2 other issues internal to a cooling unit- the Hydrogen can leak out over time (a long time though), due to slightly porous welds (and Hydrogen is a small molecule), and when the sodium chromate overheats, it releases nitrogen. The nitrogen will fill up the lower part of the unit, and is often the cause of cold freezer/warm refrigerator, as the nitrogen displaces the hydrogen in the fresh food compartment.
