Technical data

41
Alpha 240XP and 240XE - Fault Finding
10.5 FAULT FINDING SOLUTION SECTIONS A to L
NO
YES
Pump
If pump jammed, release
Replace main PCB
NO
PCB terminals 20, 21
B
Replace pump
1.
2.
240 V at:-
NO
NO
NO
NO
Main terminals L and N
Check electrical supply
Replace fuse
Replace suppressor
Check wiring
Main terminal fuse
Both sides of suppressor
PCB terminals 27, 28
A
240 V at:-
1.
2.
3.
4.
C
NO
YES
CH system pressure 1.0 bar
Re-pressurise system
Vent air, then replace pump
Replace diaphragm
Flow valve rod obstructed
NO
NO
Pump circulating water
Primary flow valve diaphragm damaged
1.
2.
3.
E
NO
Is 240 V across PCB terminals 13, N
Replace air pressure switch
YES
Check and correct:-
1. Electrical and pressure tube connections
2. Blockage of pressure tubes
3. Restriction in flue
Replace main PCB
Replace main PCB
D
NO
Continuity across primary flow microswitch and
PCB terminals 39, 40
Replace microswitch
1.
YES
YES
YES
NO
NO
DHW/Primary temp. sensor faulty. Cold resistance approx.
11 k ohms (resistance reduces with increase in temp.)
Replace sensor
2.
3.
240XE: Fan connections correct at fan and PCB
240XP: Fan connections correct at fan and PCB
Is 240 V across PCB terminals 16, 19
Is approx. 440 V across PCB terminals 17, 19
Fan jammed or faulty winding,
i.e. correct cold resistance 35 ohm
Fan jammed or faulty winding
YES
YES
Replace fan
Replace fan
Press red reset button
Is 240V at gas valve and across
ignition PCB - M2 connector, terminals I, H
240V at ignition PCB across
M1 connector, terminal D and
M2 connector, terminal F
YES
YES
F
Gas at burner
Replace gas valve
NO
NO
NO
NO
Replace reset switch
Replace ignition PCB
YES
Ensure gas is on and purged
Red reset button
illuminated
240XE
F
Replace sensor
Replace main PCB
DHW/Primary temp. sensor faulty
Cold resistance approx. 11 k ohms
(resistance reduces with increase in temp.)
NO
YES
NO
Is 240 V at gas valve and across
PCB terminals 5, 6
Replace gas valve
YES
240XP