John wrote:
"NC" wrote in message news:xKU4c.434$sg7.202@newsfe1-win...
MrCheerful wrote:
"NC" wrote in message
news:3JT4c.187$N1.178@newsfe1-win...
SNIP
Elements are very cheap and fail regularly in hard water areas. If
live was
shorted to earth the fuse would blow. Quite often a small amount of
current
will flow through the element, so a resistance test will only help if
you
first work out what the resistance should be, in your case you are
looking
for about twenty ohms across the element. If your figure is a long way
up
from this, then the element has failed. Turn the water off, disconnect
wiring, unscrew and reverse the process to install a new one. Often
not as
easy as it sounds.
MrCheerful
Thanks - confirms my thoughts - l/n resistance is in the region of
Mega/Kilo ohms! Just my luck - rented a flat in the same block for a
year - element went in there. Now bought this one and its happened
again. Block is about 3/4 years old so just about expected lifetime as
its very hard water - just my luck to catch them both !
Got an electrician in last time and will get same guy - I'm not
confident enough since my last diy job (plumbing) had a steady leak and
has ended up leaving the tiles on the kitchen floor in need of replcaing
at the water seeped slowly underneath ! Wife will insist on a pro..... 
If you have really hard water you could expect failure in much less - in
our area a standard element providing all the hot water for a family will
fail in just over a year (just out of guarantee:-( ). Insist on one of
the aggressive water types such as (Incaloy, Backerloy , Aqualoy etc)
depending on make when it is replaced. They only cost about fifteen quid
from plumb centre rather than the usual seven or eight but last about four
times as long. Also ensure your thermostat is set at a sensible level not
screwed right up to minimise the duty times it operates. 60 degrees at the
bottom of a standard cylinder will give much higher temperatures at the top
anyway, unles you have a destratification pump (rare in domestics)
Thanks for advice - currently waiting for my electrician to get in touch
when he's back from hols - until then its the shower, and kettle for
washing up !