Head Height for cold water cistern

[landrover]

Could anyone tell me what is the mionimum hieght differance between the bottom of the Cold water cistern and the hot water tap in orfer to provide a reasonable pressure on the hot water.

Having installed a bathrooom in the loft conversion we are haveing trouble obtaining a reasonable pressure

 

[doitall]

10m = 1 bar, so 1m = a trickle.

install a pump.

 

[Malc]

In my house there's about 2m, perhaps 2.5m, between the bath tap feed shower head and the top of the cold water tank. The shower works fine as long as the shower hose is the large bore type.