Fill and Flush valve

[Potatoman]

Hi, I would like to fit a 28 mm fill and flush valve to my system, but the valve reduces the bore to about 20mm for about 35mm in length, will this have any effect on the flow/ efficiency of my system. Thanks

[JohnMo]

1 hour ago, Potatoman said:

Hi, I would like to fit a 28 mm fill and flush valve to my system, but the valve reduces the bore to about 20mm for about 35mm in length, will this have any effect on the flow/ efficiency of my system. Thanks

A little, or a lot depending on flow rates, if your at 20L/min and below very little, higher rates a bigger and bigger influence - if you have UFH you can do this at the manifold anyway. So wouldn't bother, unless you have a good reason.

[Potatoman]

Unfortunately, it's all radiators

[SimonD]

When needs must..😉 This one is on 22mm but works just as well on 28mm with full bore lever valve on the primary pipework.