Plumbing wc cistern

[sparkyboy]

When plumbing in a wc cistern, do you need a double check valve on the 15mm supply pipe ?
I think I have heard that one is required under the water regs?

 

[Agile]

Thats an interesting question!

Providing the float valve incorporates the correct 20 mm air gap then you do not need a check valve on the supply.

What you do need though is an isolating valve!

Tony

 

[sparkyboy]

Thanks Agile.
Will be fitting isolating valve but how do I tell if float valve incorporates 20mm air gap? It's one of those newfangled things without a float arm but has a float which slides up and down valve body.

 

[Agile]

generally if the overflow outlet is well below where the water enters the cistern then its OK.

Most modern designs are expected to comply.

Tony

 

[sparkyboy]

Many thanks Agile, I appreciate your advice.

 

[Gunslinger]

if in doubt i'd fit one, they only cost a little, and the reduced pressure/flow is hardly likely to cause any problems on a wc cistern