Supply requirements for basin mixer and bath filler

[richardlee]

Hello guys.

I hope you could help me out here.

I am fitting a new bathroom and as part of it I am installing a new shower from a shower pump with dedicated feeds off a 50 gallon loft cistern for CW and an essex flange from the Cylinder for HW.

I will also be fitting a bath filler which is a twin lever type and a basin mixer which is a single lever type.
My feed to the bathroom at the moment is gravity HW in 22mm and mains CW in 15mm, the original bathroom had seperate hot and cold taps on bath and basin.

My question is this: Should I run a seperate gravity CW supply to the bath and basin mixer from the loft cistern? And if so, could I tee off the 22mm CW supply to the HW tank or the 22mm supply to the shower pump or must I fit another tank connector to the cistern (which will give me a total of 3 tank connectors!)? Or can I just use the mains supply for the cold? I dont think the bath filler is such an issue as it has individual controls for hot and cold but thought that the pressure difference between the hot and cold on the mixer may be an issue.

Thanks very much.

Richard.

 

[PlumbBobBob]

cold to the basin should really be mains for washing teeth etc. bath can be from cistern but i would get taps compatible with low pressure of around 0.2bar.

 

[richardlee]

Thanks Steve.
Yes, the taps are rated at min 0.2 Bar. So I guess I may as well use mains on both the basin mixer and the bath filler, saves running a seperate gravity CW. I was just concerned with overpowering the HW with the mains CW in the mixer.
Cheers for the reply.
Richard.

 

[PlumbBobBob]

richard if you fit non return valves to the hot and cold you wont have the problem of cold overcoming the hot

 

[richardlee]

Thanks Steve.
That makes sense, so a check valve on the hot and cold supply to the mixer will prevent this. I guess that this is not necessary on the bath filler as there are two separate valves on the tap? Or am I best fitting them anyway?
Richard.

 

[PlumbBobBob]

for the bath it all depends whether the water mixes in the tap body or there are seperate waterways to the spout. mixes in tap body=nrvs, no mixing in tap body=no nrvs needed.

 

[richardlee]

OK, perfectly understood Steve. Thanks again for the advice.
Richard.