Check Valve on Monobloc Basin Mixer

[TommyP100]

Planning on getting a Monobloc Basin Mixer for our new bathroom.

HW from Cylinder, CW from mains.

Obviously the CW pressure is far in excess of the cold so presume I need a single check valve on the HW inlet to stop CW entering the HW system.

(HW) 15mm pipe ----> Isolation Valve ----> Check Valve -----> Flexi Tap Tail to Monobloc

(CW) 15mm pipe ----> Isolation Valve ----> Flexi Tap Tail to Monobloc

Mixer I was planning to use is this...
http://www.screwfix.com/app/sfd/cat...EVT0CSTHZPCFEY?cId=A341141&ts=80807&id=47934#

Is the above correct?

Thanks

Tom

 

[ChrisR]

First make sure the chosen tap is designed for LOW pressure, ie from a cistern in the loft.
Then you need a check valve in the CW pipe too. If the mains fails your HW could contaminate the supply.

 

[TommyP100]

First make sure the chosen tap is designed for LOW pressure, ie from a cistern in the loft.
Then you need a check valve in the CW pipe too. If the mains fails your HW could contaminate the supply.

Thanks for the reply, little confused about the LOW pressure bit. CW is supplied from the water main entering the house in the kitchen where the kitchen sink CW branches off, CW pipe then heads up into the bathroom above and Tees with one branch off to the basin and toilet and one off to supply the bath and then onto the tanks in the loft.

Presume that this will mean that our basin CW supply will always be HIGH pressure and so a monobloc mixer as I was going to get is unsuitable as it needs a balanced pressure supply? Or can you get basin mixer taps suitable for unbalanced systems?

Just done some rough experiments and found the HW flow is about 8 l/min and cold is about 18 l/min.