Immersions are a fantastic, simple and cheap winter working solution that have many benefits but it is not a genuine or economic hot water solution.
I'd consider it as an option for the winter but only if I could buy a tank that had something like a metal plate pre-installed to make it something like on a hot water cylinder. I just don't like the idea of an immersion fitted direct into a plastic tank personally and certainly don't want to risk ruining mine.
I love new 'toys' but I can't help feeling it could be prove an expensive toy once the novelty wears off.
Many have done this before me, years before me and ive not read any posts of plastic tanks melting lol. Theres quite a distance between the actual element and the plastic tank where you fix the nut, if that was your worry. But certainly i wouldnt recommend this in a ibc tank that some seem to use in back of their van.
My tank is insulated with the silver backed bubble wrap insulation, twice over. Which is why my tank holds the temperature all day really well, infact well into the night.
But not just for warming the van against frost in winter or to have warm hoses but also superior cleaning. For instance next time a bird poops on your own windows leave it for a couple of days. You already know how or what its like to come of with cold water. But get some hot tap water sprayed on it and see what happens. Lol.
Wish i was getting a commision hahaha, but if anyone is considering it, i would recommend doing so.