Is it possible to get or make a hot water cylinder that is not made
from metal? Around here they are usually copper. And thieves steal
anything that's made of copper, and they have just done so, together
with all the piping and taps.
The water is heated using a solar panel, so there is no electric
element or naked flames anywhere around the tank.
The water can reach boiling point.
I was thinking of some kind of plastic tank around 100 litres, in a
box packed with fibreglass insulation.