Bathroom plumbing, check valves and regulations

[Bonoch]

Hi,

I’m in the process of remodelling my bathroom. Currently at the stage of plumbing the bath and wall hung WC. I’m planing to install a toilet douche (thermostatic, it will need hot and cold supply) and for the bath, I have an overflow Hudson Reed filler. I would like to know if these two items are both categorised as risk level 5? If yes, what do I need to install (I.e. double check valve) that can meet the regs requirement and avoid cross contamination? Also apart from the above, what other elements of house hold requires back flow prevention device and what type? FYI I have a mains supply and combi boiler system. Thanks

 

[Newboy]

You're going to need a bit more than a double check valve

Something like this is more appropriate.

 

[Madrab]

The douche is certainly Cat 5. You need it to be supplied by a separate cistern/break tank that has a suitable airgap and a separate HW cylinder.

The Overflow filler is at least Cat3 and a double check will suffice for that.

 

[Bonoch]

Thanks for your input guys. In that case it will be more cost effective and less time consuming to get rid of the douche then, shame I paid £56 for it -_- only if I realised this earlier. For the bath filler, do both supplies need double check valves or just one will suffice? Also does the shower hose and the geberit wc frame need check valves too? The shower hose head will not reach the basin nor the WC pan, and the digital valve/source is in the loft, but I just want to double check. Thanks again.

 

[Madrab]

Yes indeed, douche's they're frightful things, people that hook them to the mains don't realise they could poison themselves.

The bath filler, primarily the cold as the hot is through the boiler.

The processor for your digital shower will normally have NRV's and as long as the shower head isn't sitting in a pool of dirty water then it should be fine though a double check on the hose if you want to follow the letter of the regs.

 

[Bonoch]

I can easily add a check valve for the shower in the loft. This was very helpful. Thanks

 

[Bonoch]

You're going to need a bit more than a double check valve

Something like this is more appropriate.

What is that called please? It will be good for future reference.

 

[Madrab]

That's a pumped break tank ..... not cheap tho.