42
FAULT SOLUTION SECTIONS
H
J
K
2
Overheat thermostat operated or
faulty.
Check for and correct any system
faults (water circulation).
NO
�I
Allow to cool. Continuity
across thermostat terminals
more than 1.5 ohm
� Replace safety thermostat
'---------------'
NO
Check Flow, Return,
sensors. See section 'D'
YES
CH system pressure less than
7.25 psi or more than
4
3 psi.
Restore System Pressure
NO
Ensure correct circulation of
the pump
YES
YES
Check wiring and pcb connection at
connector x22 is there approx. 5 V
DC between the green and black
NO
terminals
Check flow temperature sensor connections
and position. Sensors swapped.
Cold resistance approximately.
1 OkO @ 77' F (CH sensors)
(resistance reduces with increase in temp.)
YES
I
• I
.I
I
Is E11 O is still flashing
Replace pressure sensor
Replace PCB
I
Replace sensor
Go to section 'B'
Is there 120V at:
PCB connector x13 3 way valve terminals
Blue to Black central heating mode
Blue to Brown domestic hot water mode
See Wiring Diagram
YES
Replace PCB
Check 3 way valve cable.
Motor, 3 way valve
Replace motor 3 way valve
Replace PCB
I
PN 240012875 REV. A [01/31/2020]
Summary of Contents for MACF-150
Page 63: ...61 A 1 MODELS 125 Heat Only APPENDIX A WIRING DIAGRAMS 240012874 REV A 01 31 2020 ...
Page 64: ...62 APPENDIX A WIRING DIAGRAMS A 2 MODELS 165 Heat Only 240012874 REV A 01 31 2020 ...
Page 65: ...63 A 2 MODELS 150 Combi APPENDIX A WIRING DIAGRAMS 240012874 REV A 01 31 2020 ...
Page 66: ...64 A 4 MODELS 205 Combi APPENDIX A WIRING DIAGRAMS 240012874 REV A 01 31 2020 ...
Page 67: ...65 NOTES 240012874 REV A 01 31 2020 ...
Page 68: ...66 NOTES 240012874 REV A 01 31 2020 ...
Page 99: ...29 MODEL 150F Combi 150F FLOOR STANDING COMBI WIRING DIAGRAM PN 240012875 REV A 01 31 2020 ...
Page 101: ...31 205F FLOOR STANDING COMBI WIRING DIAGRAM MODEL 205F Combi PN 240012875 REV A 01 31 2020 ...
Page 106: ...36 Low Water Cutoff Detail LOW WATER CUTOFF NO NO YES PN 240012875 REV A 01 31 2020 ...
