Shower Pressure

[stevelewis]

Hi all, i'm new here and I just have a quick question that I figured someone on here might be able to answer.

We have an Ideal Isar combi-boiler in our house which has been playing up a little recently, we had a plumber out and he messed about with it and it seems to be working okay now.

But the last couple of weeks our shower has been playing up, every time we turn it on it works fine for 5-6 minutes then the pressure drops and it starts to whistle (sounds like air escaping through the shower head).

It's an older most likely cheap (fitted by previous owners) mixer shower as far as I can tell (it's mounted into the wall with just a temperature knob sticking out).

Had a different plumber out today, one that is supposed to be reputable locally he said he thinks it's most likely the "shower thermostat" and that we are best buying a new shower.

I'm not 100% convinced that it isn't the boiler playing up again, and I thought these mixer showers just literally mixed hot & cold water and there shouldn't be anything in it that would cause this pressure loss.

My question to you all is, does it sound likely and should I pay for a new shower?

I look forward to your responses
-Steve

 

[doitall]

Does the boiler play up when you run hot water elsewhere.

 

[stevelewis]

No. thats the confusing thing, the hot water is fine and piping hot to run a bath or either sink.

 

[stevelewis]

Does anyone have any ideas about my above question?

 

[dazzler39]

its obviously a fault with the shower if all other hot outlets are working,