Is this an isolation valve?

[Wedge2017]

...it's on the hot inlet to my bath tap (and I am wanting to replace the bath...). No other isolation valve apparent between immersion and tap. A hex key in the inner opening just rotates as if worn, the outer is more than twice the size of any hex key I have and although the outside is ribbed, i cannot turn the white plastic using mole grips....

thoughts?

Thanks,
W.

 

[aptsys]

It's a check valve.

 

[Elkato531]

The valve to shut off your hot water should be on the pipe feeding cold water into the bottom of your hot water cylinder.

 

[Madrab]

Do you have a combi boiler with no tanks/cylinders or a hot water cylinder with a cold water storage cistern above it, either directly or in an attic?

 

[Wedge2017]

It's a check valve.

Thanks Aptsys

The valve to shut off your hot water should be on the pipe feeding cold water into the bottom of your hot water cylinder.

...which was kind of going to be my next question - yes, I found this and it does indeed shut off the hot water feed - Thanks

Do you have a combi boiler with no tanks/cylinders or a hot water cylinder with a cold water storage cistern above it, either directly or in an attic?

Hot water cylinder with a cold water storage cistern above it.

Cheers,
W.

 

[Madrab]

If that's a check valve, never seen one like that (every day's a school day) and your hot water is gravity fed then I'd remove it. All it will be doing is causing a flow restriction, is the hot water flow very slow?

 

[Wedge2017]

If that's a check valve, never seen one like that (every day's a school day) and your hot water is gravity fed then I'd remove it. All it will be doing is causing a flow restriction, is the hot water flow very slow?

The mixer tap instructions that I am about to install state that "If supplies are not of equal pressures then non-return valves should be fitted"

 

[Madrab]

That's only relative if you have mains cold water and tank fed hot water. If that's the case then yep a check valve would be advised but I'd replace the one that's there as it's unusual and you won't know if it works or not.