PS probably in a long horizontal run with a sag in the middle.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

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"Tim+" wrote in message
...
A couple of months ago I fitted a thermostatic mixer for a friend to
provide warm water to an outside tap for dog showering purposes. I was a
little uneasy about it working well with a gravity HW system and mains
cold
but the manufacturer assured me that it would work.

Indeed, it did work fine until recently when it started to exhibit weird
behaviour. Now when you turn on the tap, nothing comes out. No water at
all, neither hot, cold or warm. If you leave the tap open for a few
minutes, the water starts flowing and it seems to work fine. I tried
tapping on the valve to see if maybe this would free a stuck non-return
valve but it had no effect.

This is repeated on a daily basis. Can anyone explain this behaviour?

Tim

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