fitting mixer shower but confusd re: backsiphonage

[flyfto]

i am confused, i am trying to position where to put my shower controller and shower head !
but in the manual it is saying the shower head when dangling down has to be at least 25mm above the over spill level of the bath !!!!
but in order to do this my shower controller would be up to high.

there is a hose retaining ring on the showerhead adjustment pole !
can i just use this retaining ring to achieve the 25mm asked for.

also what exactly does it mean by "backsiphonage " ? i looked into it but cant get my head round it !!


cheers

 

[jobloggs]

Back syphonage: Theoretically if the shower head is left lying in the bathwater and the cold feed is mains fed then under some situations you can have a drop in pressure in the mains to such a degree that bathwater is syphoned back into the mains.

This is also the reason an outside tap must have a check valve in case the end of an attached hose is left in a puddle of dirty water

I am not up to speed with regs but if your cold and hot feed to the shower are both fed from a storage tank in loft then this coud not happen so not a problem. If shower feeds are mains fed it might be possible to put a double check valve on the mains after the stopcock but you would have to ask some of the experts on this site.

 

[flyfto]

my feed for shower is def mains pressure !
can anyone confirm if its worth fitting a check valve and also can anyone confirm my original worry, where too install the shower control

cheers for any advice

 

[lightning]

there is a hose retaining ring on the showerhead adjustment pole !
can i just use this retaining ring to achieve the 25mm asked for.

yes that what it is for,so the shower head does not reach the bottom of the bath

 

[flyfto]

that answers my question actually thanks very much.

gettin in a kiffuddle over nothin, as usual lol

 

[BoxBasher]

Yup,

Retaining ring is for that sole purpose.

Don't tell my colleagues but my shower head can dangle in the bath even with the retaining ring

New bathroom getting delivered tomorrow though so I'll whack the DCV on when I'm in the middle of a refit.

The joys of buying a house eh? not got too much more to put right. Just the garden tap and kitchen to do...