Installation - gledhill StainlessLite Plus Direct D90 Instruction Manual

INSTALLATION

General Design Considerations
The cupboard footprint needs to be at least 650mm square for standard units up to
300 litres, 730mm for 400 litre and 575mm for slimline units. The base chosen for the
cylinder should be level and capable of supporting the weight of the unit when full of
water as shown in General Data. The discharge pipework for the safety valves must have
a minimum fall of 1 : 200 from the unit to a safe discharge point. All exposed pipework
and fittings on the cylinder should be insulated, and the unit should NOT be fixed in a
location where the contents could freeze.
In new systems, pipes should be insulated to comply with building regs, the maximum
permissible heat loss is indicated in the table opposite, and labelled accordingly as follows:
i. Primary circulation pipes for domestic hot water circuits should be insulated
through their length, subject only to practical constraints imposed by the need
to penetrate joists and other structural elements.
ii. All pipes connected to hot water storage vessels, including the vent pipe, should
be insulated for at least 1 metre from their points of connection to the cylinder (or
they should be insulated up to the point where they become concealed).
In replacement systems, whenever a boiler or hot water storage vessel is replaced in
an existing system, any pipes that are exposed as part of the work or are otherwise
accessible should be insulated as recommended for new systems, or to some lesser
standard where practical constraints dictate.
The pipe connecting the boiler flow to the appliance must not be less than 22mm
copper or equivalent.
Standard and Slimline Model Selection Guide
Max number
Max hot water demand of bed spaces
(Bedrooms)
1 shower room Bedsit (0)
1 bathroom 2 (2)
1 bathroom 4 (3)
1 bathroom + separate shower room 6 (4)
1 bathroom + 2 separate shower rooms
7 (5)
or 2 bathrooms
2 bathrooms + separate shower room 7 (5)
2 bathrooms + 2 separate shower rooms 7 (5)
3 bathrooms + 2 separate showers rooms 9 (6)
Solar Model Selection Guide
Max hot water demand Bedrooms
1 shower room Bedsit
1 bathroom 1-3
1 bathroom 1-3
1 bathroom + 1 shower room 1-3
1 bathroom + 1 shower room 1-3
1 bathroom + 2 shower rooms 2-4
1 bathroom + 2 shower rooms 2-4
2 bathrooms + 1 shower room 3-4
2 bathrooms + 2 shower rooms 4-5
INSTALLATION
Insulation of pipework
Pipe outside Maximum
diameter heat loss
15mm 7.89W/m
22mm 9.12W/m
28mm 10.07W/m
35mm 11.08W/m
Further guidance on converting heat loss limits
to insulation thickness for specific thermal
conductivities is available in TIMSA "HVAC
guidance for achieving compliance with Part L
of the Building Regulations".
Mains Water Supply
Existing properties with a 15mm supply will be
satisfactory provided the local mains pressure is
good, but should be confined to single bathroom
properties. For new properties where simultaneous
demand is required to more than one bathroom
or a bathroom and one or more en-suites, the
communication and service pipe into the dwelling
should be a minimum of 22mm (usually in the
form of a 25mm MDPE supply). The optimum
performance is achieved if the inlet pressure is
3 bar dynamic. However, the StainlessLite Plus
will function with lower inlet pressures, but
Indirect Direct
this will reduce the performance. For optimum
litres litres
performance, 30L per minute incoming mains flow
90 120 should be present, however the StainlessLite Plus
will work at lower flow rates, although performance
120 150
will be affected. Normally StainlessLite Plus
120 180
provides well in excess of 40 litres/min in most
150 210
conditions. Flow rates for ALL mains pressure
systems are subject to district pressures and system
180 210
dynamic loss. Particularly on larger properties with
more than one bathroom, the pipe sizes should be
210 250
calculated in accordance with BS EN 806-3:2006
250 300
and BS 8558:2011.
300 -
Model Selection
The suggested Direct model sizes, shown
opposite, are based on a typical days hot water
use assuming an Economy 7 tariff is provided.
Indirect Direct
A reduction of one model size can normally
litres litres
be made with an Economy 10 tariff. When
- 180
using the Direct models for high specification
180 - developments an increase of one model size
should be considered.
210
210 -
The suggested model sizes are based on typical hot
- 250 water usage. For high specification dwellings an
increase of one model size should be considered.
250 -
- 300
300 -
400 -
Page 12
General Restrictions
a. The highest hot or cold water draw off point should not exceed 10 metres above
the Pressure Reducing Valve.
b. An ascending spray type bidet or any other appliance with a Class 1 back-syphonage
risk requiring a type A air gap should not be used.
c. StainlessLite Plus should not be used where steam is the primary heating medium,
or in a situation where maintenance is likely to be neglected.
d. Unvented cylinders are not suitable for use with solid fuel boilers.
e. If the supply to the mixer fittings (other than a dual outlet type) is not taken from
the balanced supply the system will become over pressurized and cause the
pressure relief valve to discharge. Over time this could also cause the premature
failure of the appliance itself which will not be covered by the warranty.
f. In larger properties with a number of bathrooms/en-suites and long pipe runs
we would recommend that the balance cold supply is provided with its own
pressure reducing valve and is not taken from the balanced cold connection on
the combination valve. In this case it will also be necessary to fit a small expansion
vessel on the balanced cold water system to accommodate the pressure rise caused
by the increase in temperature of the balanced cold water.
g. Check the performance requirements of the terminal fittings with regard to flow/
pressure are suitable.
h. In relation to potable water systems, expansion vessels shall be installed in a vertical
orientation and located so that the length of the connecting pipe work is kept to
a minimum.
Shower Fittings
Aerated taps are recommended to prevent splashing. Any type of shower mixing valve
can be used as long as both the hot and cold supplies are mains fed. However, all mains
pressure systems are subject to dynamic changes particularly when other hot and cold
taps/showers are opened and closed, which will cause changes in the water temperature
at mixed water outlets such as showers. For this reason and because these are now no
more expensive than a manual shower we strongly recommend the use of thermostatic
showers with this appliance. These must be used in 3 storey properties where the
impact on pressure/temperature of opening another tap in the system is greater than
normal. The shower head provided must also be suitable for mains pressure supplies.
DHW
SH
P&T
ERV/NRV
PRV
SCV
WM or DWM
TO SINK
EXTERNAL
TAP
DC
DC
M
DC
WATER SOFTENER (IF NECESSARY)
INCOMING COLD SUPPLY
INSTALLATION
Pipe Layout
In all mains pressure installations it is important
to remember that the incoming cold supply
must be shared between all terminal fittings. It
is important that a 22mm supply is brought to
the appliance and a 22mm take-off is continued
at least to the bath. If there are two baths, 28mm
pipework should be considered. One metre of
smaller diameter pipework, or flow restrictors,
should be provided on the final connection to
all outlets so as to balance the water available.
In any event the distribution pipework should
generally be in accordance with BS EN806-1 to 5.
Plastic Pipework
This appliance is suitable for use with plastic
pipework as long as the material is recommended
for the purpose by the manufacturer and is installed
fully in accordance with their recommendations.
Secondary Hot Water Circulation
All models 210 litres and above are fitted with
a secondary return tapping as standard (see
tables 1 and 2 for details). If fitted, an extra
expansion vessel may be necessary. A non-
return valve MUST be FITTED near the return
connection. No valve or terminal fitting should
be installed between the non return valve and
the cylinder. (See schematic arrangement on
page 15.) All pipes kept hot by the secondary
circulation should be insulated.
Note:
Cold supplies to single taps must be
taken from the mains cold water
WHB
system.
WC BATH
Cold supplies to mixer taps must be
taken from the balanced cold water
connection on the combination
SCV valve.
WHB
W.C.
DCV
DC
DC
INSTALLATION
Page 13