21
The boiler operating mode is controlled by the selector switch on the facia panel.
When the selector switch is set to 'ON' the boiler will provide central heating.
6.1
CENTRAL HEATING MODE
If there is a call for heat, the pump will start to circulate the central heating water. The fan will run and the pre-mix burner will light.
The burner output then automatically adjusts to suit the system demand; as the temperature of the water in the boiler approaches
that set by the adjustable temperature thermostat, the burner output is reduced. When the set temperature is reached, the burner
is turned off. The fan continues to run for 50 seconds and the pump continues to run until the temperature within the boiler reduces
to the set temperature before allowing the burner to relight. If the primary sensor has not registered the pre-set temperature but the
room thermostat is satisfied the burner is turned off. The fan continues to run for 50 seconds and the pump continues to run for 60
seconds. In this instance there is no delay before the burner will relight.
Note:
If the system pressure is very low, the primary pressure switch will prevent the boiler from operating.
6.2
FROST THERMOSTAT
The boiler incorporates a built in frost thermostat which automatically turns on the boiler and pump if the water in the boiler falls
below 8°C, providing the electrical supply is on and the selector switch is set to position (1) or position (2). The boiler will
operate until the water temperature in the system reaches approximately 40°C.
6.3
PUMP
If the electrical supply is on and the boiler has not operated for 24 hours for heating or hot water, the pump will operate
automatically for five minutes every 24 hours.
6.4
INDICATOR NEONS
When neons A (red), B (red), C (yellow), D (green) are illuminated, the following conditions apply:-
Neon
D
Illuminated continuously - Electricity supply to the boiler is on.
C
Illuminated continuously - Burner is alight.
A
Flashing on and off - Temperature sensor fault.
B
Flashing on and off - Overheat thermostat has operated. Rotate selector switch to the reset position (3) to reset.
B
Illuminated continuously - Burner has failed to light. Rotate selector switch to the reset position (3) and the ignition
sequence will restart after a delay of about 30 seconds.
A
and
B
Flashing on and off at the same time - Blocked flue or fan fault.
A
and
B
Flashing on and off alternately - System pressure is very low and re-pressurisation is required.
A
Flashing and
B
Illuminated continuously - Pump fault or restricted flow.
Note:
Do not hold the selector switch in the reset position (3) for more than 2 to 3 seconds.
Alpha CD18S/24S/30S - Boiler Operation
6
BOILER OPERATION
Содержание Alpha CD18S
Страница 11: ...11 Alpha CD18S 24S 30S General Boiler Information Fig 9 External soakaway Fig 8 External gully ...
Страница 29: ...29 9 1 ILLUSTRATED WIRING DIAGRAM Alpha CD18S 24S 30S Wiring Diagrams 9 WIRING DIAGRAMS ...
Страница 30: ...30 Alpha CD18S 24S 30S Wiring Diagrams 9 2 FUNCTIONAL FLOW WIRING DIAGRAM ...
Страница 32: ...32 10 2 FAULT FINDING SOLUTIONS A to E Alpha CD18S 24S 30S Fault Finding ...
Страница 33: ...33 Alpha CD18S 24S 30S Fault Finding 10 3 FAULT FINDING SOLUTIONS F to K ...
