Shower Problem - Flow stops

[MJMIreland]

I would appreciate some good informed advice on where to look for problem with one of my sisters showers which had "stopped working" after about 5 years daily use. I had a look yesterday and this is what I found.

She has a booster pump in airing cupboard which has a cold feed from attic storage tank, and hot supply from a standard cylinder. Both of the pump cold and hot outlets divide on a T in the pipework within airing cupboard to supply 2 thermostatically controlled showers. 2nd shower works perfectly without issue so pump and supply must be ok. 1st shower behaved as follows.
Headset held high on wall mount there was no water flow when valve switched on and no action at pump. I lowered headset to shower tray and cycled valve on/off , and it kicked into life easily. I ran it for 30 seconds and replaced on wall mount and tested and all was well.
Closed everything up and went for coffee. Fixed a few other "while you are there items and then before leaving I went upstairs to 1st shower again and there was again no flow .. slight trickle .. and pump kicked in for half a second .. I again lowered and again all was flowing as required again.

As this shower is not new and worked without problem for circa 5 years , head pressure cannot be an issue as I see it. As 2nd shower running from same pump outlets runs without problem pump cannot be at fault either.

Which leaves as I see it an airlock ( but after above 30 seconds should no longer be possible I think ) or faulty valve on 1st shower. However I cannot see such a fault anywhere relating to valves so I thought I would consult here.

Any ideas appreciated .. MJM

 

[longdogs]

Have you tried removing the shower head? Could be blocked or scaled inside.

 

[MJMIreland]

Many thanks for reply Squeaky :
I removed headset but did not observe any issue. ( I may go out again and try swapping headset for a spare to eliminate it ) I don't think scale is likely to be the issue as stopping of shower was sudden according to my sister .. and her water supply is not a hard water supply.

Shower hose is not kinked in any way and as water flow is full and strong when lowering the headset and after on wall when flow established , once pump kicks in , flow path must be ok .. hence my puzzlement

many thanks ... MJMIreland

 

[MJMIreland]

An update:- Went out to sisters house yesterday. Shower has not stopped working during last 2 weeks and came on fine when I turned it on upon my arrival. As I was there I disconnected the host and headset from both showers. ( thereby disturbing the gods ! ) . I cleaned out the two filters found where hose joins wall outlet , though no real dirt found in either ) Swapped the hose/headsets , turned on main bathroom shower ( now with previous problem hose/headset ) and all was well , came on powerfully . Then I turned on en-suite shower that now had problem free hose/headset and hey presto .. no water .. pump cut in for half a sec then off ..!*!*!* disconnected hose at outlet point turned on .. water fine .. reconnected hose and no water .. then I discovered something that may or may not be the issue .. the headset is adjustable to vary the shower water pattern as many are, and at a precise certain point the adjustment wheel reaches a point where water is switched OFF altogether at the handset. Cannot believe this is related but my thought was that if my sister had been adjusting this at start of this problem while say cleaning down shower she may have set it in this position unintentionally and if all of the gods lined up I may have accidentally set it this way when fiddling at it and moving it around etc .. A bit of a very long shot but I cannot find any other problem, so for now I have adopted a wait and see approach. My thanks to all here that assisted. MJM