Installing a Power Shower

[zand108]

Hi,

I want to install an over the bath "power shower" (A shower unit with an integrated pump) I am thinking of:

The Mira Event XS Thermostatic Shower

I have not yet bought it so any comments about this shower or other "power shower" recommendations would be greatly appreciated.

I have had 4 plumbers in who all want to supply the shower by teeing off from the bath taps. This house has chronic problems with trapped air in the central heating system, which I would rather not have transferred over to the new shower but when I insist on having dedicated hot/cold feeds to the shower to avoid this they all beg off saying it's too much work and try to undermine or bully me into teeing off the baths (as it's easier for them) . I don't see why I should be made to feel silly for not being prepared to fork out money in the hope that "it will all work out fine", when I am prepared to pay a bit more for it to be done properly in the first place, I might still have an air problem either way. but at least I'dve done all I could to avoid it.

Anyway I have had enough so I am gonna try to install it myself (Just the plumbing not the electrics I am still bloodied from crossing swords with Part P during a kitchen refit and have no desire for a rematch) I have spent the last few days reading through the posts on this forum and so have "some" idea of what I will be doing but I would like the experts to go over my plans and let me know if I am missing anything.

My setup is as follows:
The hot/cold tanks are in an airing cupboard approx 5m away (as the crow flies) from the bathroom and 6.5m (as the crow flies) from where I would like the shower to go.
The route I would need to take to get the water from the airing cupboard to the shower is 10M long and would go under the floor to the bathroom then up the wall to the shower.

The system is gravity fed from a ~50 gallon cold water cistern that is ~1.9m off the gound. This supplies a 140L hot water cylinder that sits 80cm directly beneath it.
Cold water is fed from the cistern into the bathroom via 22mm copper pipe. The cylinder is supplied by 22mm copper pipe from the cistern and feeds hot water into the bathroom via 22mm copper pipe which comes out of the cylinder horizontally before teeing off vertically to the vent pipe and the pipe that leads to the bathroom fittings as illustrated below.

==

After reading the instruction manual & some of the posts on this site and talking to Mira I realise that the two biggest problems I face are:

1) That the average shower unit is placed ~150mm off the ground. With such a low cistern only 186cm off the ground and such a long supply pipe run ~10M maintaining a sufficient enough head for the shower to operate without reduced flow rate, spluttering and temperature
fluctuations may be a problem.

I want to use 22mm JG Speedfit Barrier Coil Pipe with the 22mm Cold Form Bends to do without elbow joints all the way up to the shower unit and then step down to 15mm with a JG Speedfit 22mm-15mm reducer and then connect to the inlet port on the shower with either 15mm JG Speedfit Rotating Elbow Stem or 300mm/1000mm Long Speedfit Flexi Hose.

This way will require less pipe and will mean that I won't have to put any connectors under the floor where I wont have any access to them should they fail.

2) The low cistern head/horizontal orientation of the pipe leaving the cylinder will increase the risk of trapped air and cavitation Mira recommends installing air vents to help resolve this is there anything else I can do?

[Updated as I accidentily submitted before I was finished]

 

[seco services]

can you not run the pipework up in loft then down to shower rather than under all the floor?

 

[zand108]

...Continuing here as I "submitted" when I should have "previewed"

2) Although Mira advise against it could installing an Essex Flange with an "u" shaped bend in the pipe coming off of it be a good idea to tackle air bubbles/cavitation. That seems to be the general consensus in a lot of the posts I have read but does the configuration of my pipework make any difference???

I know I have to install service/isolation valves would either of these be recommended?

JG Speedfit Plastic Service Valve 22mm
or
JG Speedfit Plastic Ball Valve 22mm

 

[zand108]

can you not run the pipework up in loft then down to shower rather than under all the floor?

Mira have advised against a high-level hot feed pipe run and since I will be struggling to get a decent head as it by running under the floors I don't know if that's a good idea to go high.

Besides I am putting new laminates on the corrider and new floor tiles in the bathroom so it should not be that much more work!

 

[rssteve]

quote - This house has chronic problems with trapped air in the central heating system.

Am i missing the point that your heating will effect your cold water supply for your shower, or are you confused that the heating system is not directly connected to the cold water?

 

[seco services]

powershowers like yours i always tee off the horizontal pipe from the cylinder and tee downwards.

i always use these they are full bore isolation valves
the others your pointed out restrict inside and are not full bore.

http://www.toolstation.com/images/library/stock/webbig/18591.jpg

most times i run up and other the loft to showers
and fit bleed valves to remove any trapped air at the highest point.

 

[zand108]

can you not run the pipework up in loft then down to shower rather than under all the floor?

Mira have advised against a high-level hot feed pipe run and since I will be struggling to get a decent head as it by running under the floors I don't know if that's a good idea to go high.

Besides I am putting new laminates on the corrider and new floor tiles in the bathroom so it should not be that much more work!

Also my ceilings are almost 3m high so it would probably take the same amount of pipe even if I were to go through the loft... But thanks anyway

 

[zand108]

Thanks for responding Seco & so quickly too!!

Teeing off the horizontal pipe is exactly what Mira recommended but so many people on this site have adamently argued for using an Essex Flange that I thought it was almost standard practice to do so when installing pumps & things.

Why do you prefer to go through the loft rather than under the floor??

Which bleed valves do you use? and where in my setup would you recomend putting them.

 

[seco services]

if im fitting a mixer shower with a pump next to cylinder i run them off a surrey, essex flange etc.
if im fitting a powershower like yours i come off the horizontal pipe, or tee off the vertical pipe below the horizontal pipe.

9/10 times i take the hot feed up to the loft and run the hot/cold across the loft then down wall into shower fitting these at highest point in pipework in loft.

http://www.screwfix.com/app/sfd/cat...HZPCFFQ?productId=19155&imageNo=null&ts=74305

 

[zand108]

quote - This house has chronic problems with trapped air in the central heating system.

Am i missing the point that your heating will effect your cold water supply for your shower, or are you confused that the heating system is not directly connected to the cold water?

Sorry I missed your post.

I am probably the confused one.

But I have problems with trapped air in the heating system the dry runnung pump makes a god awful noise & I regularly have to bleed the pump to clear it & I have trouble with the cold water sometimes the water splutters out of the taps or shoots out like its under pressure & often no water comes out of the taps at all . Luckily this only ever happens during the early hours of the morning.

So I just figured the two problems were somehow related.

 

[seco services]

wheres the cold tap water supplied from mains or tank ?

as for your heating pump check your small tank in loft see if its filling or muck in the bottom.
also your heating maybe drawing in air down vent pipe.

 

[zand108]

if im fitting a mixer shower with a pump next to cylinder i run them off a surrey, essex flange etc.
if im fitting a powershower like yours i come off the horizontal pipe, or tee off the vertical pipe below the horizontal pipe.

9/10 times i take the hot feed up to the loft and run the hot/cold across the loft then down wall into shower fitting these at highest point in pipework in loft.

http://www.screwfix.com/app/sfd/cat...productId=19155&imageNo=null&ts=74305[/QUOTE]

Thanks again for the advice very very interesting. How do those bleed valves work? are they automatic (does the trapped air pass without assistance) or manual (if the shower starts playing up will I have to climb naked into the loft to bleed these valves).

How are they installed and will they work with speedfit pipe??

 

[seco services]

once your pipework and shower is up and running you shouldn't get air in the pipework unless you drain the tank/cylinder. so no need to bleed.

if you insert a brass tee into your pipework then you can have a airvent on the tee at highest point so you can bleed the pipework when installing shower.

you can get manual, automatic, solder,compression etc.

 

[zand108]

Seco thanks you have been terrific,

I have to admit you have got me well confused now I don't know whether I should be going up or down. Hopefuly you can be a bit more specific on the merits/disadvantages of the loft vs floor route and also answer the following questions:

1) Is it ok to use 22mm speedfit barrrier coil for the whole pipe run & only step down to 15mm for a few cm to make the fit into the shower inlet ports?

2) I'll be vertically teeing off the horizontal hot pipe (No flanges for me!!!) if going into the loft do you tee vertically upwards or downwards first then turn up to the loft? Also can I tee off in speedpipe or do I need to tee off in copper for a bit first???

3) For the cold I'll drill a new hole into the cistern and run a dedicated pipe to the shower is it ok to use this JG Speedfit Tank Connector.

4) Do you usually fit the isolation valves in the loft?

5) Does the cold pipe need an air vent as well.

6) Do you see a problem with placing the hot water air vent immediately after the tee off the horizontal pipe as if I go under the floor this will likely be the highest accessible point in the run?

6) Do you usually fit check valves/NRV valves for this type of application??

 

[zand108]

Ok done more research and am quietly confident that I have it all worked out .

Gonna go along the floor for three reasons:

1) The loft space is very long and quite cramped and the entrance is far from where I want to run the pipe from making thinks tricky.

2) I am a bit on the heavy side and the joists up there don't seem all that stable to me.

3) Honestly this is the clincher "Its flippin' DARK & SCARY up there !!!"

So instead I am gonna run long lengths of 22mm Speedfit pipe from the airing cupboard to the bathroom and use speedfit connectors for all connections.

Gonna put speedfit flexi hoses on the end of the pipe runs to make it easier to connect to the shower inlet port and so that the pipes can be (somewhat) repositioned should I install a different make of shower in the future.

Gonna install isolation valves in the airing cupboard on the vertical tee for the hot (close to the tee so that I don't have to bend too low) and on the dedicated cold at a similar height.

Gonna install single check valves under the bath on the way to the shower I can remove the bath cover the access them should they fail.

Not gonna install air vents yet as I am going through the floor but if problems develop then i'll put them at the highest accessible points in the system which will be in the airing cupboards somewhere between the vertical tee and the isolation valve on the hot and high on the dedicated cold close to the cistern.

Hope this sounds all right.

Thanks!