Water Supply; Water Systems And Pipe Work - Worcester Greenstar Highflow 440CDi ERP Installation, Commissioning And Servicing Instructions

PRE-INSTALLATION
3.2.3

Water supply

WATER MAINS PRESSURE:
• Minimum mains water pressure, for maximum performance refer to
table 6 - Technical data.
• Maximum mains fed water pressure 10 bar.
If necessary fit a pressure reducing valve.
NOTICE: Non return, flow back prevention devices
(including those associated with water meters) fitted to
the mains water supply can cause a pressure build up
which could damage the boiler and other household
appliances.
• Where the mains water supply has a non-return, flow back
prevention valve fitted, a mini expansion vessel [1] should be
connected to the mains water inlet pipe [2] between the non-return
valve [3] and the boiler [4] as shown below.
1
2 3
Fig. 3 Mains water pressure
1 Mini expansion vessel - part no. 7 716 192 105
2 Mains water inlet pipe
3 Non return valve
4 Boiler
USE IN HARD WATER AREAS:
Normally there is no need for water treatment to prevent scale formation
as the maximum temperature of the HW heat exchanger is limited by the
electronic control.
In areas where temporary water hardness exceeds 200ppm,
consideration may need to be given to the fitting of a scale prevention
device. In such circumstances, the advice of the local water authority
should be sought.
3.3

Water systems and pipe work

PRIMARY SYSTEM PLASTIC PIPEWORK:
• Any plastic pipe work must have a polymeric barrier with 600mm
(minimum) length of copper connected to the boiler.
• Plastic pipe work used for under floor heating must be correctly
controlled with a thermostatic blending valve limiting the
temperature of the circuits to approximately 50°C. The pipe work
from the boiler to the blending valve must be in copper.
PRIMARY SYSTEM/CONNECTIONS/VALVES:
• Do not use galvanised pipes or radiators.
• All system connections, taps and mixing valves must be capable of
sustaining a pressure of 3 bar.
• Radiator valves should conform to BS2767:10.
• All other valves should conform to BS1010.
• On new installations a TRV should be used on all radiators except the
radiator where the room thermostat is sited, this must be fitted with
lock-shield valves and left open.
• All installations should have a TRV fitted to radiators within the
sleeping accommodation.
• Drain cocks are required at all the lowest points on the system.
• Air vents are required at all high points on the system.
12
4
6720643895-04.1Wo
SEALED PRIMARY SYSTEM:
• Where the system volume is more than 100 litres or exceeds 2.5 bar
at maximum heating temperature an additional expansion vessel [2]
must be fitted as close as possible to the appliance in the central
heating return.
• Pressurise the extra expansion vessel [2] to the same value as the
built-in expansion vessel - refer to table 6 - Technical data.
2
1
4
3
Fig. 4 Typical sealed system
1 - Appliance expansion vessel
2 - Additional expansion vessel
3 - Pressure relief discharge
4 - Drain cock
5 - Radiators
FILLING PRIMARY SYSTEMS:
• The boiler is fitted with an integral filling loop system and can be used
to fill the system.
• The CH sealed system must be filled using a WRAS approved filling
loop or comply with the diagram below for external system fill.
• The filling point must be at low level and must never be a permanent
direct fixing to the mains water supply.
SYSTEM FILL
- External option
Heating
return
Hose union
SV
2
1 3
0 bar 4 Temporary
*
hose
Pressure gauge
Fig. 5 External filling option
[*] Pressure gauge - If the external filling link is sited away from the
boiler, then a pressure gauge should be installed at the filling
point
SHOWERS/BIDETS:
• If a shower head can be immersed in water or comes closer than
25mm from the top edge of a bath or shower tray spill over level then
an anti-siphon device must be fitted to the shower hose.
• Bidets with direct hot and cold mains water can be used (with the
approval of the local water authority) and must be the over rim
flushing type with shrouded outlets to prevent the fitting of hand held
sprays.
DOMESTIC HOT WATER:
• Taps and mixing valves must be capable of sustaining a pressure up
to 10 bar.
• Hot water temperature and flow rate are affected by the size and
insulation of pipe work making up the distribution system and are
controlled by the hot water tap and the water main inlet pressure. A
mixing valve can be fitted if a more permanent temperature setting is
required.
• If using more than one outlet at once causes water flow starvation, fit
flow balancing valves or Ball-O-Fix valves to the appropriate outlets.
Greenstar Highflow CDi
5 5
5 5
4
Mains
supply
CV CV
SV
Test point
CV = Check Valve
SV = Stop Valve
ErP - 6720818077 (2016/04)