On 2007-01-28 00:26:13 +0000, EricP said:

On Sun, 28 Jan 2007 00:08:02 GMT, Siggy
wrote:


See above. Then suicide, if that doesn't work ...

As the crucifix seems to have stopped working, this may be the only
path left.

You must try to find the leak. With no puddles on the floor, it is
probably going out the pressure relief valve, or even across to the
DHW side and out the tap.

Have you examined the relief valve?

Have you looked at the pressure vessel?

Another one along these lines is leaking spindles on radiator valves.
A small leak may only be happening when the system is hot and of an
amount that it is evaporated by the heat without showing very much or
at all from the caps. Try going around and removing each cap for a
look. Replace any radiator valves showing signs of leaking with new,
good quality ones such as Pegler. Spindles of motorised valves are
another candidate.

Pressure relief valve is certainly a favourite. If this is leaking,
then a replacement is the solution since they are impossible to repair
reliably.

Concerning a thorough system clean; a better approach, which would not
have issues with different materials and use of chemicals, would be to
remove each radiator in turn, take it outside and flush it with a
pressure washer or hose on the mains. While the radiator is removed,
flush system water out at the radiator position from the valves.
This means that crud is flushed out and not around the system and is
much more effective than circulating an acid cleaner.
Care, because sludgy water is an indellible dye. Small sandwich bags
rubber banded over radiator tails is a good plan while moving them
around.

An alternative that would be better than adding a cleaner and
circulating would be to rent a pressure flushing machine and use that
to power flush the system.