Curious if anyone might know anything more along these lines - Running a UTH on a thermostat against the bottom of a rubbermaid tub, would I ever need to worry about the UTH ever potentially melting the plastic? I know that when it's on a thermostat there really isn't a risk since I don't let it go much over 100 degrees to keep the hotspot on the inside of the tank at the right temperature (93 right now), but I've read too many horror stories here and across the internet about thermostats failing and allowing the UTH to go unregulated for periods of time.
This is a total worst-case-scenario, but could letting an unregulated UTH run against the plastic of a tub cause it to melt?