18
Alpha CD90S/115S - Commissioning
When commissioning the boiler, ensure the Benchmark Checklist is completed.
5.1
FILL THE SYSTEM
1.
The boiler is fitted with an automatic air vent positioned as shown in Fig. 3, ensure that the vent is always open.
2.
Open any central heating flow and return valves.
3.
Open the fill point valve on the filling loop until water is heard to flow.
4.
To remove the air - Vent each radiator in turn, starting with the lowest in the system.
5.
It is important that the pump is properly vented to avoid it running dry and damaging its bearings. Unscrew and
remove the cap from the centre of the pump. Using a suitable screwdriver rotate the exposed spindle about half a
turn, then replace the cap.
6.
Check the operation of the pressure relief valve (see Fig. 3) by turning the head anti-clockwise until it clicks. The
click is the valve lifting off its seat allowing water to escape from the system - check that this is actually happening.
7.
Continue to fill the system until the pressure gauge indicates 1.0 bar. Close the fill point valve and check the system for
water soundness, rectifying where necessary. Disconnect the filling loop from the mains supply. If the system has been
over pressurised water may be released from the system by manually operating the drain point (see Fig. 3) until the
system design pressure is obtained. The system design pressure (cold) should be between 0.75 and 1.25 bar.
Refer to Sections 3.9 and 3.10. Filling and Flushing the system.
5.2
TEST FOR GAS TIGHTNESS AND PURGE THE SUPPLY
1.
With the boiler gas service cock
closed. Pressure test the gas supply
and inlet pipework connection to the
boiler gas service cock for tightness
in accordance with BS 6891.
2.
Loosen the gas inlet pressure test
point screw on the gas valve (see
Fig. 21). Ensure the gas supply is
on and open the boiler service cock
to purge in accordance with BS
6891.
3.
Retighten the test point screw and
test for gas tightness. Close the
boiler gas service cock.
5
COMMISSIONING
Fig. 22
On/Off switch
Pressure gauge
Display panel
ON
MODE
STEP
STORE
+
-
RESET
Alpha
5.3
BOILER CONTROLS - Fig. 22
Fig. 21
5.4
INITIAL LIGHTING - Refer to Fig. 22
1.
Ensure that the gas and electrical supplies to the boiler are off and that any heating flow and return valves are open.
2.
Turn on the gas and electrical supplies to the boiler.
3.
Ensure any external controls are calling for heat.
4.
Set the On/Off switch to ON. The boiler will now run in the central heating mode. The pump will start, the fan will start
and the main gas valve solenoid will open allowing the main burner to light.
Inlet gas
pressure
test point
Outlet gas
pressure
test point
Outlet flow
regulator
Off-set
adjustment
screw
P1
P3
