Shower on Combi Boiler (Hudson Reed)

[Oddjob]

Hello everyone, I'm planing to install a shower over the bath on a combi boiler by using a thermostatic mixing device feeding into a fixed shower head.

I have been looking at the Hudson Reed mixers.

The combi is in downstairs kitchen with bathroom directly above. The hot water pipe will go straight up into the bathroom.

Because the shower head is built in, I assume the only way of fitting it to the wall is by building a false wall from plaster board and then tiling over it. The wall in question is already a partion wall - I originally thought of just cutting a channel into the wall for the pipes - but I can't work out how the head will then be fixed as it bolts from the other side.

Has anybody got any advice or tips about doing this? Has anybody got experiance with using Hudson Reed gear?

Many thanks

[David Kennedy]

Get one with an adjustable head. Miras do one which works well with our combi.

[Andrew Gabriel]

Sorry, never heard of Hudson Reed.

You need a thermostatic shower specifically designed for use with a combi or multipoint. These are designed for high pressure cold and very widely varying pressure hot, and have very fast response time on the thermostat. The common cheaper wax phile types don't work well with combis/multipoints -- besides being too slow to react to temperature and pressure changes, they use the wrong mechanism to change the water temperature and it's ineffective.

[Oddjob]

That is a very good point - the one I was looking at is wax operated - I will continue my ressaserch :-))

[Oddjob]

Andrew, been looking on the web for alternative transducers. The information is very hard to find. Nobody seems to publish response times and if it was not using wax phile then what would the technology be?

I'm thinking about using a standard mixer with a pressure equalisation valve. The range of showers available is bewildering.............

[Andrew Gabriel]

I think they use bi-metal spirals. Look for showers which claim to be designed for combis and multipoints. When I got mine about 7 years ago, Gainsborough did mine in 3 models -- IIRC, low pressure (from header tank), low hot and high cold, and the combi/multipoint version with high cold and widely varying hot. The first two could be switched between by respositioning a part, but the combi/multipoint version had completely different innards (and was quite a bit more expensive -- I bought it in an end-of-line sale).

That's part of what a combi/multipoint mixer is. The other part is fast acting, and knowing it can't adjust the temperature of the shower by changing flow rate of the hot water (less true of the top-end combis which tend to have fixed temperature output).

These will also be less of an issue in a single person flat than in a house with many familty members and appliances varying the hot water loading/pressure.