49
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
FAULT SOLUTION SECTIONS
PN 240011430 REV. P [09/15/2021]
Summary of Contents for 100
Page 34: ...34 MODEL 125 Heat Only 125 HEAT ONLY WIRING DIAGRAM PN 240011430 REV P 09 15 2021 ...
Page 35: ...35 MODEL 165 Heat Only 165 HEAT ONLY WIRING DIAGRAM PN 240011430 REV P 09 15 2021 ...
Page 36: ...36 115 COMBI WIRING DIAGRAM MODEL 115 Combi PN 240011430 REV P 09 15 2021 ...
Page 37: ...37 MODEL 150 Combi 150 COMBI WIRING DIAGRAM PN 240011430 REV P 09 15 2021 ...
Page 38: ...38 MODEL 205 Combi 205 COMBI WIRING DIAGRAM PN 240011430 REV P 09 15 2021 ...
Page 43: ...43 Low Water Cutoff Detail LOW WATER CUTOFF NO NO YES PN 240011430 REV P 09 15 2021 ...
Page 48: ...48 3 FAULT SOLUTION SECTIONS PN 240011430 REV P 09 15 2021 ...
