Leaking pressure sensing pipes

[Teknophobia]

Hi all, first post so be nice!

Boiler is a Combi 102 (Halstead/Wickes).

Initial problem was no DHW but CH okay. Correctly identified as a split diaphragm. In replacing this part (£31!!!), had to remove the pressure sensing pipes from the flow switch body which were held in place by spring clips (and a red seal).

Have put the pressure sensing pipes back in using the spring clips but both pipes are now leaking heavily. The o-rings in both look okay, so my only option was to seal them using a water/heatproof sealant. This did not work initially (gave it 5 hours to set) so isolated the Cold Water In ball valve which then broke! Turned water off at the mains and re-applied sealant. This morning, switched water back on and no leakage, but no hot water either (CH okay). I guess the ball valve got stuck in a closed position.

My questions are: Has anyone dealt with a similar issue on the pressure sensing pipes before? What did you do? Why did Halstead design it this way? Will replacing/fixing the valve create more pressure and cause the pipes to leak again when the cold water is opened?

Thoughts/advice appreciated.

 

[ChrisR]

99.9% likely you simply didn't get them in far enough before putting the clip in. Get new O rings, and lube with silicone grease. Clean out your goo first of course.
They are hard to get in if not dead straight, and without the right tools, which we find out the hard way.

 

[Teknophobia]

Thanks for the reply ChrisR,

I made sure the pipes were all the way in by using a wedge to keep the pipes in place whilst attaching the clips. This was necessary as the pipes were very loose fitting and kept dropping out.

I did notice that the pipe which leaked the most was at a slight angle to the flow switch body.

I may try getting new/larger O rings if it continues to be a pain. Thanks for the suggestion.