I replaced the switch on the water heater again. This is the 4th melted switch in 2 months. When it works (which it's doing on both electric and propane at the moment) it works fine. There is no sign of damage but it's 13 years old.
I can only think of two possibilities:
1) there is some worn insulation and occasionally the wire shorts out and melts the switch
or
2) I got some counterfeit switches from Amazon. They're supposedly rated 20A @ 125V but maybe not.
Just curious did you ever replace the heater? Throwing parts at an issue is never the best way to go about it. But I think a replacement heater is only around $20. I personally would have a concern on the idea of adding a more robust switch. To me that is akin to just adding a bigger fuse.
