6.0 System Details
15
© Baxi Heating UK Limited 2005
6.6
Domestic Hot Water Circuit
1. All DHW circuits, connections, fittings, etc. should be
fully in accordance with relevant standards and water
supply regulations.
2.When installed in accordance with 1 above this
appliance does not require a check valve to meet water
supply regulations. However when the system includes
any device which prevents water expanding back
towards the supply, then an expansion vessel must be
fitted (e.g. Zilmet 160ml, R
1
/
2
15 bar).
3. 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.
4. The boiler’s maximum working mains pressure is 10
bar (150 lb/in2), 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.
5. Optimum hot water delivery of 16 l/min (133 model),
12 l/min (100 model), 10 l/min (80 model) may be
obtained by fitting the flow regulator supplied.
6.7
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.
6.8
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. Contact your
Water Distribution Company for advice on suitable
devices.
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
Boiler
Other Tap
Outlets
Expansion
Vessel
To Hot
Taps
Check
Valve
Pressure Reducer
Valve
Stop Tap
V
M
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
1
5
4 3 2
20
21
7
18
17
14
12
9
11
16
19
13
10
15
6
8
15