In article ,
Mike Hall wrote:
May seem like a silly question, but is 3-4 years normal even when the
immersion heater is not used?, (ours is a backup for the gas boiler
which heats the tank by indirect coil).

Mine didn't work after about 10 years or so - apart from a test when
installed. Can't say when it *actually* failed though. I replaced it with
a stainless one and do check it occasionally now.

--
*Laugh alone and the world thinks you're an idiot.

Dave Plowman London SW 12
RIP Acorn