Concealed Bath/Shower mixer valve and wall cavity...

[JMLanders]

An increasing number of houses do without a bath at all nowadays and rely solely on a large, walk-in shower. This could be a possible solution here.

 

[SteNova]

it's gonna be messy if the only place it can go is against the window , i think we need to see a full room layout with measurements

 

[Richard C]

after researching i've decided to go for a salamander RHP50 house pump. ideally i would install it under the bath so it would only come on when flow is selected from the shower/bath valve but there will be tap-offs for all the other services between the cws and hot water tanks and the pump which is a no no according to the manufacturers intructions. i dont really need everything else boosting so it will be a waste of pump lifespan and unnecessary noise if i just plumb it in the airing cupboard... so i'm considering making separate tap offs to install the pump in the airing cupboard and routing new pipework to the bathroom. i'm just finalising what components i need inline between the pump and the valve as i want to take the pipework through the loft (not a viable option to rip up floor boards).

Unless you really need it, an RHP whole house pump isn’t necessary & you may find that the noise of the thing continually tripping in when you turn on any hot tap is so annoying, you end up turning the thing off for except when showering; as I do in my own house which has an RHP 75.

Take separate dedicated supplies from your HWS cylinder (via an Essex flange) & CWS tank (opposite the inlet valve) & fit the pump in the bottom of the airing cupboard. If you intend to install up & over loops (through the loft) from the pump to the shower valve, you will be in a potentially negative head situation if any of the pipe work runs closer than 600mm from the bottom of the CWS tank; you need a minimum flow of 1 litre/min at the shower head or the flow switches in a standard pump won’t trigger. You will also need to vent the top of any loops or the pump will eventually air lock. Use only full bore (lever) valves for isolation; most gate valves restrict the flow.

Have you considered an ST Monsoon pump (only needs 300mm instead of 600mm), slightly more expensive but a quieter & much better pump IMO.

 

[JoelyP]

Unless you really need it, an RHP whole house pump isn’t necessary & you may find that the noise of the thing continually tripping in when you turn on any hot tap is so annoying, you end up turning the thing off for except when showering; as I do in my own house which has an RHP 75.

Take separate dedicated supplies from your HWS cylinder (via an Essex flange) & CWS tank (opposite the inlet valve) & fit the pump in the bottom of the airing cupboard. If you intend to install up & over loops (through the loft) from the pump to the shower valve, you will be in a potentially negative head situation if any of the pipe work runs closer than 600mm from the bottom of the CWS tank; you need a minimum flow of 1 litre/min at the shower head or the flow switches in a standard pump won’t trigger. You will also need to vent the top of any loops or the pump will eventually air lock. Use only full bore (lever) valves for isolation; most gate valves restrict the flow.

Have you considered an ST Monsoon pump (only needs 300mm instead of 600mm), slightly more expensive but a quieter & much better pump IMO.

i was informed that i would need the rhp for the bypass loops due to it feeding a bath filler... in case only hot or cold are selected individually. it will still only be used to supply the shower valve so not too worried about the noise with every tap in the house.

can i just tap off the existing pipe that exits the top of the hws cylinder? why do you say to tap off the cws opposite the inlet valve? all the existing tap offs are on the same side.

i will have a look at some stuart turner pumps, thank for the suggestion.

 

[Richard C]

i was informed that i would need the rhp for the bypass loops due to it feeding a bath filler... in case only hot or cold are selected individually. it will still only be used to supply the shower valve so not too worried about the noise with every tap in the house.

That’s correct; but I thought you were now considering a dedicated shower feed which would be best if you don’t need to pump other supplies.

can i just tap off the existing pipe that exits the top of the hws cylinder? why do you say to tap off the cws opposite the inlet valve? all the existing tap offs are on the same side.

Not advised as air in the H/W supply could kill your pump in a very short time & invalidate the manufacturer’s warranty. You should at least fit a top feed anti aeration flange (Surrey or Warix) for a pumped supply but a side fitting Essex flange with it's own supply pipework will give the shower a dedicated H/W supply which is by far the best. The CW shower pump feed should, again, be dedicated & opposite the tank inlet. This helps avoid aerated water (created by the pressure of the incoming C/W supply) being sucked into the pump as the tank level drops, which it will. An aerated water supply (hot or cold) is the worst enemy of any shower pump & can kill it in a very short time.

 

[JoelyP]

some sound advice, thanks chap.

it will be a dedicated feed to the 'shower valve' but the valve has a 3way selector which supplies the bath filler too. so i'll definately go for a pump with bypass loop... do the st pumps have these? seems to be unique to salamander. the salamander also seems to be much more competitively priced.

i guess i better call out a pro to fit the essex flange from the hws as it looks a bit daunting, there appears to be quite alot of negativity towards them on here too! i need to work out the capacity of the tanks now to determine how long it will take to emprty them with the various pump pressures before i take the plunge and purchase a pump.

 

[JoelyP]

An increasing number of houses do without a bath at all nowadays and rely solely on a large, walk-in shower. This could be a possible solution here.

its the way i would go but the mrs wouldn't go for that as she loves a bath.

it's gonna be messy if the only place it can go is against the window , i think we need to see a full room layout with measurements

the window is a fair way forward of the shower head but it has a waterproof roller blind over it to minimise splashes. also the room will be tiled floor to ceiling so it will be all sealed.

 

[Richard C]

it will be a dedicated feed to the 'shower valve' but the valve has a 3way selector which supplies the bath filler too. so i'll definately go for a pump with bypass loop... do the st pumps have these? seems to be unique to salamander.

I’m impressed. Both the ST Monsoon Standard (+ head only) & Monsoon Extra (+ & - head) are suitable as whole house pumps. Sally produce pumps both with a bypass loop (RHP) & without (RSP), presumably to save cost on the dedicated shower pump but it can lead to problems if you buy the wrong one!

the salamander also seems to be much more competitively priced.

Yes but the Sally pump is all composite plastic, the ST is brass; I've also found the ST is quieter in openration. I actually have a Sally RHP fitted in my own house but subsequent installation experience makes me wish I’d chosen the ST.

i guess i better call out a pro to fit the essex flange from the hws as it looks a bit daunting, there appears to be quite alot of negativity towards them on here too! i need to work out the capacity of the tanks now to determine how long it will take to emprty them with the various pump pressures before i take the plunge and purchase a pump.

Was not aware of any negative comments towards Essex flanges on here. A little more effort to fit & I must admit that the prospect of drilling a large hole in the side of your tank (especially a brand new one) won’t fill you with joy the 1st time you do it but they really aren’t that difficult to fit & are the only flange that will give you a dedicated full flow.

It’s not purely pump pressure that will dictate your tank capacity. Pressure & flow rate are variable one against the other, it’s the flow rate of your system & the shower head you chose that will determine how quickly your tanks will empty. For your average house, I would suggest a minimum 250 litre CWS & 150 litre HWS; in most cases this should give you enough supply for two longish showers, in quick succession (or simultaneously) or maximum 3 successive shortish showers.

 

[JoelyP]

you mention the monsoon range of st pumps i assume because they are house pumps but looking at the st website, the showermate range states:

A Showermate S1.8 bar twin pump is designed to boost the incoming hot and cold water supply to an individual shower, bath / shower mixer, or mixer tap.

http://www.stuart-turner.co.uk/products/showermate/s18-bar-twin

seems to fit the bill? or does it... the connections on this old girl are all 15mm whereas the inlet (and all supply pipwork i've bought) is 22mm. early advice i recieved was that 15mm supply to a bath filler is a bit weedy!

i've taken some measurements and it appears my hws tank is a measly 120 litres so i will look to upgrade that in the near future and my cws is 250 litres. earlier i mentioned my shower head size but i got it wrong, it is 8" and has the following flow rates:

FLOW RATES:
-1bar -4L
-3BAR -8L
-5BAR -16L
-8BAR-21L

 

[Richard C]

The Showermate is a budget pump, do yourself a favour spend the extra & get a Monsoon 2 bar, it will give you nearly 2 x the flow rate. A drencher head needs at least 8 l/min or will be dissapointing, are your sure yours requires 3 bar to deliver 8 litres/min.

 

[JoelyP]

according to the website yes:

http://www.ergonomicdesigns.co.uk/SH-316-8_Mirror_Shower_Head_With_Neoprene_Outlets.html

 

[Richard C]

Hmm, you seem to have picked a relatively high pressure head, you’d do better with something like this;
http://www.smrbathrooms.co.uk/acatalog/Chrome-Round-Sheer-Shower-Head-only.html

Fitted a few Hudson Reeds; this one is 0.5 bar minimum but some start as low 0.1 bar.

 

[JoelyP]

ill try the one i have and see how i get on but i will bare that hudson reed one in mind. i've got a hudson reed deck mounted shower head for the mrs' hair and the dogs!.. bloody expensive stuff!

out of curiosity, you say you have your whole house supplied with the sally and only turn it on for showering; have you wired a switch into the bathroom to turn the pump on and off or do you have to do it from the airing cupboard? it would save a fair bit of work (and money) to do it this way and use all the existing pipework.

 

[Richard C]

out of curiosity, you say you have your whole house supplied with the sally and only turn it on for showering; have you wired a switch into the bathroom to turn the pump on and off or do you have to do it from the airing cupboard? it would save a fair bit of work (and money) to do it this way and use all the existing pipework.

The Sally actually came with a 13A plug already fitted which just plugs into a 13A spur socket outlet inside the airing cupboard, along with the programmer for the central/solar heating systems we have. When not showering or running a bath, we just switch it off at a s/o but we do have a good head on the system so we can get away with the need to power the hot water taps; I upgraded our plumbing to current standards such that the only cold water tap that isn’t mains fed now is the bath.

I've actually got two of the Hudson Red heads in my own house & they work a treat.

 

[JoelyP]

do you know if the st pumps come with a plug? it says 'prewired - yes' but i assume that just means from the pump itself.

just need to decide now whether to go for the 2bar or the 3bar