Defrost Termination / Fan Delay Sensors Always Seem to Fail After Few Months

[dshevick]

I am talking about the kind commonly used on Heatcraft 1-5 ton freezer evaps, like

Heatcraft Refrigeration 5709L. They fail in some many evaporators. Anyone know why or a solution?

Thank you,
David Shevick

[cadwaladr]

Have you tried covering the cable to sensor connection with heatsink to stop moisture ingress?

[cadwaladr]

Heatshrink! spellchecker is devil's work.

[Grizzly]

Another option, if still available.
Spray the end of the probe with HT lead moisture repellent spray.
I have used Holts outboard Motor HT lead spray before now.
The metal bead at the end, if relevant expands and contracts with the temp fluctuations and this causes a capillary action drawing in moisture. Just as cad was implying.
Grizzly

[Magoo]

I am old so prefer the paragon pressure termination option on commercial type low temp evaporators. then a pump out period with out fans as a chill cycle

[cadwaladr]

There are still a lot of the paragons around I agree much better than a lot of the electronic junk!