In message , David Hemmings
writes
Well the damn boiler has locked out yet again, before i call out an
engineer again, i had a good poke around insdie the boiler (have
previoously opened up to thoroughly clean inside).

Well i noticed one thing, the water pipe at the left hand side at the
front has two sets of wires going to small cylndrical sections
attached to the water pipe. the bottom set has the wires affixed into
blocks that push onto tabs on the cylindrical gizmo. the top set are
connected to a doodah which looks like a probe on the end that slots
inside the top cylinder section, this is covered in a white paste
which i am guessing is a thermal conducting paste. I can only imagine
that these must be monitoring the temperature. The point of this is
the top attachment is quite loose, and i am guessing making a bad
connection.

Looking for the best thing to do here, i have thermal transfer
compound (for cpu to heatsink), i was going to smother the probe in
paste push in as far as it will go and pump silicone in behind it
which when it goes off should hold it firmly in place. Or should i try
to source a replacement part that may fir in snugly ? or do something
completely different.....

Well, first off look in the manual so you know what you're on about

Second, if it is the temperature sensor, check it's resistance

Thirdly, accept the fact that it's the pcb
--
geoff