Last time away I disconnected the shower hose from the mixer valve and connected a short piece oh hose to the mixer and ran it out the washroom window to shower the dogs off after one had decided to roll in sheep p**.
When the wife had a shower after reconnecting everything back to normal the shower pressure would drop to nothing before the on-board pump kicked in and kept cycling like this much to her utter disgust.
As we were leaving the be.day I just said was probably an air lock and will be fine next time after draining all down.
Next time is this weekend and am now wandering if it was an air lock or if I do have a problem.
Itbwas only the shower, washroom basin and kitchen sink worked fine....
It sounds like an air lock to me, if the kitchen side is fine then bleed the air out with water, pressurising the system again. With a pipe on instead of a shower head there is little or no back-pressure and I suspect it emptied the intermediate pipework through syphoning.
Dave.
------------- Give a man a fish and he will eat for a day,
Teach a man to fish and you can get rid of him for a whole weekend.