Benchmark Water Treatment: For optimum performance after
installation, this boiler and its associated central heating
system should be flushed in accordance with the guidelines
given in BS7593:1992 - Treatment of water in domestic hot
water systems. Full instructions are supplied with proprietary
cleansers sold for this purpose. If an inhibitor is to be used
after flushing, it should be used in accordance with the
inhibitor manufacturers instructions.
Suitable flushing agents and inhibitors are available from Betz
Dearborn Tel: 0151 4209563 and Fernox Tel: 01799 550811.
Instructions for use are supplied with these products.
13.1 Remove the appliance cabinet
Check that the electrical supply and the gas supply to the
appliance are turned off and that all the water connections
throughout the system are tight.
Open the system valves at the appliance. Refer to Fig.6 .
Remove the automatic air vent cap. Refer to Fig. 30 .
Fill the system through the external filling loop. Refer to Section
7, Sealed System.
Vent each radiator in turn.
The automatic air vent will vent the appliance.
Remove the cap from the pump and turn the shaft about a half
turn.
Replace the cap. Refer to Fig. 31.
Switch on the electricity supply (not the gas) and set the controls
to give continuous operation in the CH mode.
When the air is expelled turn off the electrical supply and the CH
control to off.
Check the pressure relief valve operates by turning the knob anti-
clockwise until it releases.
Lower the facia to gain acces to the relief valve. Refer to Fig. 32.
Water should be expelled from the discharge pipe.
13.2 Set the Expansion Vessel Pressure
The charge pressure of the expansion vessel as despatched is
0.5bar, which is equivalent to a static head of 5m (17ft).
The charge pressure must not be less than the static head at the
point of connection.
A Schraeder type valve is fitted to the expansion vessel to allow
the discharge pressure to be increased if necessary.
The expansion vessel must be charged to 0.35bar less than the
initial system design pressure.
13. Commissioning
18
Fig. 30. Appliance components and fixings
(upper assembly).
Flue hood
Overheat
thermostat
Burner fixing screw
Combustion
chamber
cover fixing
clips (2)
Auto air
vent
Fan assembly
fixing
screws (4)
Flue Gas
Test Point
Fig. 29 - Programmer Connection - Facia Position
4
3
1
1. Programmer
2. Programmer Fixing Clip
3. Pressure Gauge
4. Programmer Connector
2
Fig. 31. Pump venting.
1
2
3
1. Electrical
Connections
Cover
2. Pump
3. Cap
Reset Button
