How to adjust pressure valve

[Marnhullman]

I want to reduce the mains pressure by adjusting the valve, see photo. I've tried putting a spanner on the grey cap held in place with a screw but was unable to shift it. I'm not sure whether I should try to remove the cap or whether I should just use a spanner on the outside of the cap?

Advice please.

 

[Mottie]

You’re going to get told off by the G3 guys on here any minute now……

 

[Marnhullman]

Why? Surely this forum is to offer advice and not only to qualified plumbers? All I want to do is reduce the water pressure. Why would that be considered an unacceptable risk if there's an available adjustment on the valve?

 

[Marnhullman]

I've figured it out - it's the screw that adjusts the pressure so no need for G3 guys or you to get stressed!

 

[Mottie]

I've figured it out - it's the screw that adjusts the pressure so no need for G3 guys or you to get stressed!

Is yours on your hot water? I asked the same question a while ago but mine was to do with unvented - I thought yours was too. Mine had a little cap where you have a flat screw. Remove that and I had an Allen screw in there that adjusted the flow. The clue for me and is also on yours was the arrows and the plus and minus symbols on the head. I was told to leave mine alone! Maybe yours is just cold water in from the mains?

 

[Marnhullman]

Mine is on the cold water supply which in turn affects the pressure of the hot supply. I needed to reduce it to try to stop violent hammering in a hot tap when it is opened.

I have tried to cure the water hammer by replacing the tap and fitting a shock arrestor but it hasn't worked so the only remaining options are to reduce the water pressure or one respondent suggested I replace the tap cartridge with a ceramic one.

Good luck with your problem.

 

[Madrab]

Replacing the tap with a ceramic one will not cure the water hammer, if anything it'll make it worse. If you have a screw down hot tap, it is not that which is creating the water hammer. There is something somewhere else that is causing it.

Turning the pressure down may reduce the hammer but it isn't fixing the problem.

 

[jeff the gasman]

You swapped the wrong tap! Simples.
Not joking either.

 

[dilalio]

You swapped the wrong tap! Simples.
Not joking either.

Shut up Jeff! He doesn't need a plumber. Didn't you hear!

 

[dilalio]

Surely this forum is to offer advice and not only to qualified plumbers?

Err... Don't think qualified/experienced plumbers need advice from the diy-ers on this forum!

 

[jeff the gasman]

Why? Surely this forum is to offer advice and not only to qualified plumbers? All I want to do is reduce the water pressure. Why would that be considered an unacceptable risk if there's an available adjustment on the valve?

Maybe an adjustable valve is st to a given point for a safety reason. You obviously know lots about hydraulics so it doesn’t include your good self.
Good luck on your quest.!