15mm non-return valves

[Arthur2]

Hi all. I'm thinking that my non-performing thermostatis bar shower might be caused by a faulty non-return valve. Anyone have experience of bad non-return valves?

Thanks.

Arthur

[Andrew Gabriel]

They add considerable resistance to the flow. If the showhead can't fall into the bath/basin/WC, then you don't need them.

[Arthur2]

Thanks. We are a bunch that sit on our arses to shower so the shower head always sits in the bottom of the bath. Are there better quality non-return valves?

Arthur

[fullflow plumbing]

If your fed from an old 1/2" lead pipe and you replace it with 25mm MDPE (the blue pipe) you`ll notice no difference whatsoever in pressure but the flow rate could potentially be 4 times as great. The outside diameters of both pipes is approx 25mm, but the wall thickness of the lead pipe is much greater so reducing the flow capacity.

Get on with replacing your lead pipe, it doesn`t cost much (other than effort digging the trench) and most water companies connect them for free.

In the meantime remove the NRV`s and piece them thro and see what happens

richard