Baxi Combi 130 HE Installation & Servicing Instructions Manual page 12

Other Tap
Outlets
Pressure
Reducer Valve
Stop Tap
6
7
11
10
15
8
9
Key
1 Expansion Vessel
2 Flow Thermostat
3 Flow Thermistor
4 Flow Switch
5 Primary Heat Exchanger
6 Gas Valve
7 DHW Plate Heat Exchanger
8 DHW Flow
9 DHW Mains Inlet
10 Flow Regulator
11 DHW Flow Switch
12
Expansion
Vessel
Check
Valve
5
4 3 2
V
21
M
14
12
13
12 Gas Inlet
13 Filling Loop
14 CH Flow Valve
15 Filter
16 CH Return Valve
17 Pressure Gauge
18 Pump
19 Pressure Relief Valve
20 Return Thermistor
21 3 Way Valve
Boiler
To Hot
Taps
1
20
19
18
17
15
16
6.0 System Details
6.7 Domestic Hot Water Circuit
1. All DHW circuits, connections, fittings, etc.
should be fully in accordance with relevant
standards and water supply regulations.
2.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 I.S. 813. "Domestic
Gas Installations".
Sealed primary circuits and/or secondary hot
water systems shall incorporate a means for
accommodating the thermal expansion of water
to prevent any discharge from the circuit and/or
system, except in an emergency situation.
3.When the system includes any device which
prevents water expanding back towards the
supply (check valve, loose jumpered stopcock,
water meter, water treatment device), then an
expansion vessel must be fitted (e.g. Zilmet
l6Oml, R1/2 l5 bar). A check valve must also be
fitted on the supply as shown, to ensure efficient
operation and also to prevent the reverse flow of
hot water into the supply pipe.
4. If the hot water expansion is not provided for,
then high pressures can develop which may
result in damage to fittings and devices on the
system.
5. The boiler's maximum working mains pressure
is 10 bar (150 lb/in 2 ), therefore all pipework,
connections, fittings, etc. should be suitable for
pressures in excess of 10 bar. A pressure
reducing valve must be fitted for pressures in
excess of 10 bar. The manufacturer of any outlet
fittings, such as a shower valve, may require a
lower maximum pressure. The pressure reduction
must take account of all fittings connected to the
DHW system.
6.8 Showers
1. If a shower control is supplied from the
appliance it should be of the thermostatic or
pressure balanced type. Thermostatic type
shower valves provide the best comfort and
guard against water at too high a temperature.
Existing controls may not be suitable - refer to the
shower valve manufacturer.
6.9 Hard Water Areas
1. If the area of the installation is recognised as a
HARD WATER AREA then a suitable device
should be fitted to treat the mains water supply to
the boiler.