38
10.3 FAULT FINDING SOLUTIONS A to D
Alpha CD12S/20S/28S - Fault Finding
NO
YES
Pump
If pump jammed, release
Replace PCB
NO
PCB - X15 connector, terminals 2, 3
B
Replace pump
1.
2.
240 V ac at:-
Replace PCB
Replace PCB
Replace PCB
Replace transformer
NO
NO
NO
NO
YES
NO
NO
NO
Main terminals L and N
Check electrical supply
Replace fuse
Check wiring
Main terminal fuse
PCB - X12 connector, terminals 2, N
Neon D
illuminated continuously
A
240 V ac at:-
1.
2.
3.
NO
YES
Replace fuse
Neon D illuminated contiuously
Is 240 V ac across
PCB X6 connector terminals 1, 2
Is 26 V ac across
PCB X4 connector terminals 1, 2
PCB fuse
4.
C
Primary temp. sensor faulty. Cold resistance approx.
12-14 k ohms (resistance reduces with increase in temp.
i.e. when hot, resistance is approximately 3 k ohms)
Check and correct connections/wiring at sensor and PCB - X11 connector, terminals 5, 6
2.
1.
YES
Check resistance throughout
the range from cold to hot
Primary temperature sensor faulty
i.e. no heating
Replace sensor
D
Check and correct:-
1. Electrical connections
2. Restriction in flue
Neon A and B flashing
at the same time
YES
YES
(BUT)
1.
Replace PCB
Replace PCB
YES
NO
NO
2.
3.
Fan connections correct at fan and PCB connector X13
Fan runs at maximum speed
PCB connector, is 36 V dc across terminals 5 and 3 or 4
Fan jammed or faulty winding
Is dc volts at PCB, X13 connector:-
across terminals 5 and 4 - 34 V dc
across terminals 2 and 4 - 4 V dc
YES
YES
YES
Replace fan
Replace fan
To Next Page
Loading...
