shower valve for combi system

[jumpingjackflashman2]

hi guys, i have just fitted a shower valve which is compatible for any system including combis, do i need to fit anything else? check valves? to stop the cold flowing through and down the hot pipe etc.
thanks.

 

[taydo]

you only need check valves if the shower head whan taken off the riser will be lower than the bath.

 

[sterose]

hi guys, i have just fitted a shower valve which is compatible for any system including combis, do i need to fit anything else? check valves? to stop the cold flowing through and down the hot pipe etc.
thanks.

As a rule, you dont nomally need check valves.

you only need check valves if the shower head whan taken off the riser will be lower than [the hieght of] the bath. [i.e. below the rim of the bath]

Correct. This provision is to prevent bacteria leaking into the mains drinking water. However, so long as you keep your bath clean, and dont leave the head dangling in the water all the time (or in fact, at all!), you should be OK without the check valve.

Regarding the cold flowing back through the hot: if you have a combi, the pressures are neutral, so you dont need any povision to prevent backflow.

 

[jumpingjackflashman2]

thanks very much for your help/info much appreciated