On 15 Jan 2006 12:08:11 GMT, Ian Stirling
wrote:

Edward W. Thompson wrote:
Have just found a drip from the bottom of my hot water cylinder so I
guess its time to replace it! I need some advice.

The cylinder is probably 15 years old and is lagged with expanded
polystyrene, I guess. It is an indirect cylinder with an immersion
heater. Looking at the catalogues it appears an identical cylinder is
available with the correct configuration of inlets and outlets. So
far straight forward to replace ;-).
snip
All guidance will be much appreciated.

I'd certainly first try to see where it's leaking from - and if it's a
place where pipes go through, to give the relevant nut another 1/6 turn
or so.
If that diddn't cure it, back the nut off, put in some PTFE, clean the
surface a bit, and tighten it back up.
They rarely - though not never - leak through the wall of the cylinder.

Thanks for the suggestion but the 'drip' is appearing at the front of
the cylinder almost exactly 90° displaced from all pipe connections.
While the leakage could migrate under the insulation I doubt whether
it would migrate 90°. Further, having been 'tight' for 15 years it
seems improbable that a pipe connection should begin to leak at this
stage. Regrettably I think the cylinder itself must be leaking for one
reason or another.

The complication of fitting a 'quick recovery' cylinder is simply not
viable or economical for me. There are only two of us in a small
cottage and our heating bills are hardly a major expenditure.
Further, being in the geriatric category I simply can't be bothered to
modify the pipe work, as will likely be required. Thanks for the
suggestion.

The cold water supply to the cylinder is 22mm but the CH connections
are smaller (18mm?). I can isolate the cold water but not both sides
of the CH boiler connection to the heating coil. I know it makes most
sense to drain down especially as I need to replace a few of the
radiator thermostatic control valves. I suppose I better 'bite the
bullet ad do the job properly.

Thanks for the advice re immersion heater. I suppose I can buy a
cylinder complete with immersion heater and thermostat fitted. The
present cylinder looks as though it was a fully assembled unit judging
from how it is insulated.

Off to B&Q, Wickes and Plumbase this morning!