Is there such thing as an anti-siphon trap for 15mm copper?

[james smith]

I have a shower head that comes vertically down out of the ceiling.

It's fed from a long pipe run above and to the left of it, sadly this means that when the shower is turned off the water is siphoned from the pipe (drawing the water off because the shower head is lower than the lateral pipe run above it) and drips for quite a while.

Is there such thing as an "anti-siphon trap" for 15mm copper pipe? Is there any other way to correct this design?

I still have access to the ceiling and pipework as it's just been installed.

Thanks

 

[Dan Robinson]

https://www.toolstation.com/shop/Taps+&+Showers/d240/Shower+Valves/sd3000/Shower+Check+Valve/p87136

 

[oldbuffer]

I'm not sure the check valve would work, as the water is being drawn in the normal direction of flow.

If you had the room, you could fit a loop (up, horizontal, down) immediately before the shower with its high point higher then the other end of the pipe. Probably wouldn't work if your shower is pumped, but OK with a combi or un-vented hot water system.

 

[dilalio]

Worth a try as the pull on the check valve may not be enough to open it... resistance might be enough ?!

 

[oldbuffer]

Dilalio's point is a good one, and its certainly a cheaper and less disruptive first option.

 

[james smith]

Thanks, this is all really helpful. I added @oldbuffer 's solution but unfortunately because the water is being siphoned it still passes through the "S" bend. I will try the check valve next.

 

[Hot&Cold]

Is there such thing as an "anti-siphon trap" for 15mm copper pipe? Is there any other way to correct this design?

first check the shower head is 100% level.
Usually the installer will be aware of residual water being siphoned out via the shower head and install accordingly to lessen the nuisance . The copper horizontal supply pipe needs to rise as much as possible in the ceiling void or loft then drop down with a pulled bend and fit the shower connector.

have overcome the siphon effect caused by extended horizontal pipe run by fitting a check valve (insert) in the shower head connection or in a ball joint if fitted.
Also changing the shower head (to a slim design by a known manufacture) can rectify the problem,some hold more water than others and promote siphon effect.

Plumbing

 

[Dan Robinson]

I fecking hate plumbing

 

[james smith]

Thanks all, really helpful.

Would a single check valve that close to the shower head have much noticable impact on flow? I am thinking of a cheap screwfix one, rather than the more expensive full flow options from Arrow.

Or should I go with a double check?