5.6
Connecting diagrams
5.6.1
Filling information
A
Domestic hot water mains inlet
B
Central heating return
C
Stop valve
D
Double check valve (Not supplied)
E
Loop (Temporary or Permanent)
A filling point connection on the central heating return pipework must be
provided to facilitate initial filling and pressurising and also any subsequent
water loss replacement/refilling.
The filling method adopted must be in accordance with all relevant water
supply regulations and use approved equipment.
Your attention is drawn to:
for GB: Guidance G24.2 and recommendation R24.2 of the Water Regu
lations Guide.
for IE: the current edition of I.S. 813 Domestic Gas Installations.
A
Cold mains in
B
Heat return
The sealed primary circuits may be filled or replenished by means of a
temporary connection between the circuit and a supply pipe, provided a
"Listed" double check valve or some other no less effective backflow pre
vention device is permanently connected at the inlet to the circuit and the
temporary connection is removed after use.
When the optional permanent filling link is fitted it is not necessary to re
move any part of it after filling or re-pressurising.
5.6.2
Domestic hot water circuit
A
Boiler
B
Expansion vessel
C
Check valve
D
Pressure reducer
E
Stop tap
F
To hot tap
G
Other tap outlets
All DHW circuits, connections, fittings, etc. should be fully in accordance
with relevant standards and water supply regulations.
Your attention is drawn to:
for GB: Guidance G17 to G24 and recommendation R17 to R24 of the
Water Regulations Guide.
for IE: the current edition of IS 813 Domestic Gas Installations.
The Water Regulations recommendations for England and Wales prohibits
backflow from appliances into the wholesome water supply due to thermal
expansion. However this type of instantaneous combination boiler, with
less than 15 litres of stored capacity, does not require any backflow pre
vention device as any thermal expansion is accommodated within the ap
pliance. It is possible in certain circumstances that other cold water de
mands (e.g. washing machines, flushing of WCs) may affect the DHW
function of the boiler. In these instances the fitting of a backflow prevention
device and expansion vessel is recommended.
Fig.25
System filling circuit
PN-0000347
A
B
C
C
D
E
Fig.26
Circuit plan
PN-0000350
A
B
G
C
D
E
F
5 Before installation
7678846 - A - 22052017
37