Where does the PRV need to go?

[gregd72002]

I think you should look into getting the cold water and hot water having exactly the same pressure. What's the difference in pressure when measuring?

I'd suggest one of the following:
PRV on cold and PRV on hot supply set in the same way
or one PRV on the mains supply to your property


Btw, I believe the noise comes from your PRV as the hot water hits the PRV from the wrong side and PRV falls into hesitation not being able to regulate pressure as the hot and cold share the same mains

 

[whitedot]

The whining noise is definitely coming from the shower valve.

Thanks for the replies though folks, I think I'll just have to tell him that I want the PRV moved for my peace of mind, even if adjusting it in situ appears to 'work' in eliminating this noise. It just doesn't appear to be the right setup.

 

[denso13]

I think I'll just have to tell him that I want the PRV moved for my peace of mind

With respect, it's nothing to do with peace of mind. It needs to be changed because it hasn't been done right. Worst case is the shower could be damaged and could be expensive to sort out.

 

[Dan Robinson]

I'm off to find a wall to bang my head on.

Cya

 

[whitedot]

I'm off to find a wall to bang my head on.

Cya

Seems a bit harsh?

It's not easy telling someone who's saying they have experience of being right that they're wrong. I'm not a professional plumber, just a homeowner of slightly over one year. Hence asking on here.

 

[whitedot]

I think I'll just have to tell him that I want the PRV moved for my peace of mind

With respect, it's nothing to do with peace of mind. It needs to be changed because it hasn't been done right. Worst case is the shower could be damaged and could be expensive to sort out.

Message understood.

As it happens, I've tested the mains pressure and it's around 5.5 bar at present. Though the Mira manual doesn't clearly specify a recommended pressure as such, it states that the 'max maintained pressure' is 5 bar. Do I even need the PRV anywhere? Is 3 bar for both feeds still preferred?

 

[silverback]

The pressures MUST be balanced, so the PRV should be on the mains before the combi, otherwise your cold has a higher pressure than the hot at the shower, this will cause a problem with the thermostatic mixer and is why you are getting fluctuations and noise, tell your builder to move it so that you have equal pressures, if your builder refuses, tell him you will get a plumber to do it and bill the builder

 

[HERTS P&D]

I'm off to find a wall to bang my head on.

Make sure there is not a PRV in the wall, it might get damaged.

Andy

 

[Dan Robinson]

OP I am not having a go, but how many people need to tell you the same thing - including the shower manufacturer?

Pressures fluctuate... you may have 5.5bar now. Tonight you could have 7.

 

[whitedot]

OP I am not having a go, but how many people need to tell you the same thing - including the shower manufacturer?

Pressures fluctuate... you may have 5.5bar now. Tonight you could have 7.

Just wanted a few people to confirm what I suspected that's all. As I said it's kind of awkward when you're trying to tell someone who installs bathrooms for a living that what they've done is wrong based on what you've read on the internet. He's considerably older than me and a friend of my dad which complicates things, I don't feel entirely comfortable just telling him what to do. If it was some random I'd employed then I wouldn't hesitate.

Anyway, I'll get it sorted you'll be happy to know.

 

[gregd72002]

Just out of nowhere - to give you something to think about

I heard and experience myself whining noise from mixer tap before and this was due to issues with shower head. Exchanging shower head resolved it!

Enjoy!