Do check valves restrict flow rate All aspects of plumbing questions and answers, help, tips and information

[barryomoss]

I am fitting an overflow filler to my bath. I have been told that check valves are necessary to prevent any waste getting back into the water supply. Are they really necessary and will they slow down the flow rate into my bath?

[speedygonzarlis]

if you have a gravity system and your header tank isnt so high you may get a restriction of flow, if combi or unvented should be fine.

[rosebery]

Yes they are required. Flow rate will be marginally affected.

Cheers

[barryomoss]

Thanks speedygonzarlis and rosebery.