"Tim+" wrote in message
...
michael adams wrote:


It appears its not the actual contact but the heat being radiated (?) by
pipes potentially being up to 120C over prolonged periods which may cause
the problem

So you're taking the calibrated scale of a thermometer as an indication of
typical CH water temperatures?

Er, no ? As I said above, it's the pipes themselves which are 120C, it being
a pipe thermometer, after all. Not necessarily a CH water thermometer, at
least as far as I know.

Quite what the relationship between the two may be I don't claim
to know But it's the temperature of the pipe rather than the water
inside it, which is of the most relevance here.

And its relationship of that temperature - in the confined space of a
hole don't forget, to the temporaries at which it's claimed the
plastic components of a co-ax lead may start to soften which is
of most potential interest.


michael adams

....