Squealing Shower

[skybluescooby]

Hi All,
We had a new shower fitted last year and over the past few months we have noticed an ever increasing horrible squealing sound when its on.
To give as much info as possible its a Mira 9.5kw Electric Shower and is in the en suite with the water tank in the loft.
We have a hot water tank on the landing.
When the shower is turned on and the dial set to high but cold the water shoots out and no noise is heard. When you turn the dial towards the red dots the pressure drops and the squealing starts. If i shake the shower hose the squealing noise changes as well. If i turn the shower to the last red dot it becomes red hot and the squealing quietens down.
I have also noticed that a build up of a reddish brown stuff is visible around the shower head nodules after 2 or 3 weeks use.

Any ideas how this noise can be stopped as its doing my head in when i want to get a shower.

 

[gasmataz]

There is a small pressure reducing thingy(cant think of the name for the life off me) just sits in the hose to shower head sounds like they missed it out.

 

[gasmataz]

Also make sure there is not any blockages. I had a squealing shower that was missing the thingy and it had a filter which was all clogged with jointing compund from the compression elbows from the loft.

 

[skybluescooby]

There is a small pressure reducing thingy(cant think of the name for the life off me) just sits in the hose to shower head sounds like they missed it out.
Can't seem to find one of those and the assembly instructions / diagram does not show anything like that at all ???

Also make sure there is not any blockages. I had a squealing shower that was missing the thingy and it had a filter which was all clogged with jointing compund from the compression elbows from the loft.
The noise has started over the last few months and getting worse so i'm guessing it could be a blockage but why does it squeal only when water is warm/hot and not cold ?

Done a bit of digging around and on another forum someone said he had Mira out to replace the flow valve ? hmmmmmmmm

 

[seco services]

you are correct a faulty flow valve can cause the mira shower to squeal.

 

[skybluescooby]

Just an update for future reference should anyone experience the same problem.
Rang Mira up on Monday afternoon, Shower has 2 weeks of warranty left. Engineer came out on Wednesday with a flow valve in hand (didn't need prompting), replaced it and it's al brand new again and working like a shower should work.
Thanks for the advice guys.