5
1 INTRODUCTION
The fittings covered by these instructions should be installed in accordance
with the Water Regulations published in 1999*.
Ideal Standard strongly recommends that these fittings are installed by
a professional fitter.
*A guide to the Water Supply (Water Fittings) Regulations 1999 and the Water Byelaws 2000, Scotland is published by
WRAS (Water Regulations Advisory Scheme) Fern Close, Pen-y-Fan Industrial Estate, Oakdale, Newport, NP11 3EH.
ISBN 0-9539708-0-9
These thermostatic shower mixers are designed to be installed on normal UK low pressure storage tank fed
systems, unvented high pressure systems, modulating instantaneous water heaters or modulating combina-
tion (combi) boilers. They are suitable for all pumped applications.
WATER REGULATIONS
Hot and cold water supply pressures must be reasonably balanced and from a common source - both from
storage or both from a supply pipe. (IRN 101). The mixers will function within specification on unequal pres
-
sures up to a ratio of 5 : 1, but it is not recommended that the cold supply be connected to the rising main
and hot to the tank fed supply as the pressure differential is likely to exceed the 5:1 ratio.
(See table 1)
The
minimum pressure for correct operation is 0.1 bar (1m head). Pressure head is measured as the vertical
distance between the bottom of the cold water storage tank which feeds the hot water system and the high-
est point on the shower spray plate. When installing with a shower pump the use of a secondary tapping
from the cylinder is highly recommended.
The picture below shows the various methods of connecting the hot water pipe to the cylinder - the most
preferred on the left and the least preferred on the right.
The fitting should be so installed as to be readily accessible for examination, repair, replacement or opera
-
tion. (IRN 111).
The temperature of the hot water must not exceed 85ºC but the installer’s attention is drawn to code of
practice BS 6700 which recommends that stored hot water should normally never exceed 65ºC. For correct
operation of the valve, a minimum of 55ºC is required.
most preferred solution
least preferred solution
Essex flange 22mm
Surrey flange
22mm outlet
From vertical
expansion pipe
22mm pipework
Figure 1
Preferred arrangements for cylinder tapping
From underside of
expansion pipe off-set
at 60º 22mm pipe
wo
rk
In accordance to BSEN1111 & BSEN1287 the valve has approval for the following applications:
High and Low Pressure HP-S and LP-S: A5877AA, A5878AA, A5958AA & A5959AA (shower valves)
High Pressure HP-S and HP-T: A5879AA & A5880AA (tub fill/shower mixers)
Note:
If water supply is fed by gravity then supply pressures should be verified to ensure the conditions
of use are appropriate for the valve.
