"1tim23" wrote in message
...

Wrote:
1tim23 wrote:


When I fit a new (backup) immersion heater I'm a little nervous of
using too much or too litte force (I suspect the old cylinder is now
leaking due to the stresses caused by fitting the old i/h).

Why, is it leaking at the immersion heater boss?


It suddenly started leaking near the IH boss for no apparent reason,
after not being touched for 9 years. A plumber took a look at it,
swapped the IH for a new one, found the leak was still there, then
pronounced that a new cylinder was required. The same thing happened
last time the cylinder had to be replaced, 9 years ago (but a different
plumber !). The story that plumber spun me was that if the cylinder
gets dented or stretched by over-tightening the IH, it forms a thin
point in the copper wall that is vulnerable to pin-hole corrosion. The
latest cylinder did indeed have a dent near the boss, as if the IH
spanner had pressed against it during tightening.

Don't know if any of this makes sense, but I want to avoid the same
fate for cylinder number 3.

Get your self a high flow combi and be done with. No more space consuming
cylinders to rot.