XSol Diagnostic System

VAILLANT TURBOMAX PRO 28E

GLOBALLY REPLACED

Next: &1, *

APPLIANCE APPEARS SATISFACTORY

Next: nff

VAILLANT TURBOMAX PRO 28E

GC NO. 47 044 11

Next: &3, !f2

OPERATIONAL SEQUENCE

Next: &364, !f189

DHW FLOW RATE

Next: &650, f6

PUMP RUNS (CH DEMAND)

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: &39, f321

DOES THE FAN RUN

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: &53, f40

ELECTRODE SPARKING

ON/OFF SWITCH IN ON POSITION

Next: &69, f54

BURNER ESTABLISHED

ON/OFF SWITCH IN ON

Next: &96, ?74, ?577, ?1040, ?1050

DHW DEMAND

DHW TEMPERATURE SELECTOR TO MAX

Next: &102, f836

DHW MAXIMUM BURNER PRESSURE

ON/OFF SWITCH IN ON

Next: &1111, ?103, ?105, ?309

CH OPERATION

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: &173, ?149, ?151, ?183

BURNER MODULATION

ON/OFF SWITCH IN ON

Next: &179, f174

PUMP OVERRUN

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: &181, !f180

ANTI-CYCLE

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: &nff, !f182

ENHANCED FAULT CODES

Next: &5, !f365

FLAME INDICATOR FLASHING - SENSOR FAULT

OUTSIDE MODEL

Next: &nff, f1102

IGNITION INDICATOR FLASHING - LACK OF WATER / CIRCULATION

OUTSIDE MODEL

Next: &nff, f432

FLAME INDICATOR ILLUMINATED WITH NO DEMAND - FALSE FLAME

OUTSIDE MODEL

Next: &nff, f466

BURNER LOCKOUT INDICATOR ILLUMINATED - IGNITION LOCKOUT

Next: &nff, f476

BURNER LOCKOUT INDICATOR FLASHING - INTERNAL FAULT

OUTSIDE MODEL

Next: &nff, f500

FUSE FURTHER INVESTIGATION (DUMMY)

OUTSIDE MODEL

Next: &nff, f621

OBSERVATION DISPLAY ILLUMINATES

ON / OFF SWITCH ON

Next: &13, f652

HOW TO SET MULTIMETER TO DIODE

THE IMAGES BELOW SHO

Next: &nff, !f705

FAN INDICATOR ILLUMINATED - APS SHORT

NOT USED - HEADER FOR FAULT CODE

Next: &nff, f1061

FAN INDICATOR FLASHING - APS NOT PROVING

NOT USED - HEADER FOR FAULT CODE

Next: &nff, f1073

DHW OPERATION

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MIN
DHW TEMP SELECTOR TO MAX

Next: &148, ?1112, ?1114, ?1116, ?1118, ?1120

DHW FLOW FLOW RATE

LIMITER

Next: End

NO PRESSURE SIT VALVE

GAS VALVE AND PCB

Next: End

LOW PRESSURE

GAS VALVE INLET PRESSURE

Next: End

FLAME SENSE

CABLE TREE

Next: End

FLAME SENSE BURNER ESTABLISHED

IGNITION C/W MONITORING ELECTRODE

Next: End

BURNER

BURNER CHAMBER GROUP

Next: End

BURNER IGNITES SPARKING CONTINUES THEN LOCKOUT

TUBE - DISTRIBUTOR (BURNER INJECTOR)

Next: End

BURNER ESTABLISHED

IGNITION C/W MONITORING ELECTRODE - GAP

Next: End

FAN INDICATOR ILLUMINATED

TUBE - FLEXIBLE

Next: End

FAN INDICATOR ILLUMINATED

VENTURI

Next: End

FAN INDICATOR ILLUMINATED

FLUE

Next: End

FAN INDICATOR FLASHING

PCB

Next: End

FAN INDICATOR FLASHING

CABLE TREE

Next: End

FAN INDICATOR FLASHING

TUBE - FLEXIBLE

Next: End

FAN INDICATOR FLASHING

VENTURI

Next: End

FAN INDICATOR FLASHING

FLUE

Next: End

FAN INDICATOR FLASHING APS NC

CABLE TREE

Next: End

FAN INDICATOR FLASHING

SWITCH - FAN PROVING - HUBA

Next: End

F0/F10 FAULT CODE

SENSOR - NTC

Next: End

F11/1 FAULT CODE

SENSOR - NTC

Next: End

DHW TOO HOT

SENSOR - NTC

Next: End

DHW TOO HOT

SET - 3 KNOBS + LEVER (GREEN)

Next: End

WEAK OR SLOW CAUSING KETTLING

PUMP ASSEMBLY - GRUNDFOS VP5

Next: End

DHW OPERATION

AUTOMATIC BY-PASS

Next: End

DHW COOL RADIATORS HOT

PCB

Next: End

WEAK OR SLOW CAUSING POOR DHW TEMPERATURE RISE

PUMP ASSEMBLY - GRUNDFOS VP5

Next: End

DHW OPERATION

TUBE - DISTRIBUTOR (BURNER INJECTOR)

Next: End

DHW OPERATION

PRIMARY HEAT EXCHANGER FLUE WAYS

Next: End

DHW OPERATION

FLUE

Next: End

DHW MAXIMUM BURNER PRESSURE

PRIMARY HEAT EXCHANGER FLUE WAYS

Next: End

DHW FLOW RATE

FILTER - WATER

Next: End

DHW MAXIMUM BURNER PRESSURE

FLUE

Next: End

BOILER HEATS BUT RADS COLD

AUTOMATIC BY-PASS

Next: End

CH OPERATION

PUMP ASSEMBLY - GRUNDFOS VP5

Next: End

CH NOISY DHW OK

AUTOMATIC BY-PASS

Next: End

BURNER MODULATION

SENSOR - NTC

Next: End

PUMP OVERRUN

PCB

Next: End

ANTI-CYCLE

PCB

Next: End

OPERATIONAL SEQUENCE

SYSTEM CHECKS

Next: End

ELECTRICAL SAFETY CHECKS

ELECTRICAL SAFETY

Next: End

HONEYWELL VALVE

GAS VALVE INLET PRESSURE

Next: End

NO BURNER PRESSURE

SYSTEM PRESSURE

Next: End

BURNER ESTABLISHED

GAS VALVE INLET PRESSURE

Next: End

BURNER EST

WATER PRESSURE SWITCH

Next: End

BURNER ESTABLISH

HARNESS GAS VALVE AND WATER PRESSURE SWITCH

Next: End

HONEYWELL ELECTRICAL

GAS SECTION

Next: End

BURNER DROPS OUT

PRIMARY HEAT EXCHANGER FLUE WAYS

Next: End

BURNER DROPS OUT

VENTURI

Next: End

BURNER DROPS OUT

FAN

Next: End

BURNER DROPS OUT

TUBE - FLEXIBLE

Next: End

BURNER DROPS OUT

FLUE

Next: End

CH OP

PCB

Next: End

FAULT CODES

Z REDIRECT

Next: End

F20 - STUCK IN FAULT

PCB

Next: End

OVERHEAT

SYSTEM PRESSURE

Next: End

F20 RUNNING SLOW

PUMP ASSEMBLY - GRUNDFOS VP5

Next: End

FAN RUNS (CH DEMAND)

TUBE - FLEXIBLE

Next: End

F20 FAULT CODE

SENSOR - NTC

Next: End

F20 FAULT CODE

SENSOR - NTC

Next: End

OVERHEAT3

PCB

Next: End

FAN RUNS (CH DEMAND)

VENTURI

Next: End

F27 FAULT CODE

CABLE TREE

Next: End

F27 FAULT CODE

IGNITION C/W MONITORING ELECTRODE

Next: End

FAN RUNS (CH DEMAND)

FLUE

Next: End

F28 FAULT CODE

IGNITION C/W MONITORING ELECTRODE

Next: End

F28 FAULT CODE

IGNITION C/W MONITORING ELECTRODE - GAP

Next: End

FAN RUNS (CH DEMAND)

PCB

Next: End

F60 FAULT CODE

CABLE TREE

Next: End

F60 FAULT CODE

Z REDIRECT

Next: End

HARNESS FAN

CABLE TREE

Next: End

F20 - NO POWER TO PUMP

PCB

Next: End

ELECTRODE SPARKING

TUBE - FLEXIBLE

Next: End

ELECTRODE SPARKING

VENTURI

Next: End

ELECTRODE SPARKING

FLUE

Next: End

APS NC

CABLE TREE

Next: End

ELECTRODE SPARKING

IGNITION C/W MONITORING ELECTRODE

Next: End

ELECTRODE SPARKING

IGNITION C/W MONITORING ELECTRODE - GAP

Next: End

BURNER ESTABLISHED ELECTRICAL

GAS SECTION

Next: End

NO PRESSURE SWITCH

GAS SECTION

Next: End

NO PRESSURE SWITCH

GAS VALVE INLET PRESSURE

Next: End

FUSE INVESTIGATION

TRANSFORMER

Next: End

FUSE INVESTIGATION

PUMP ASSEMBLY - GRUNDFOS VP5

Next: End

FUSE INVESTIGATION

FAN

Next: End

FUSE INV SIT

GAS SECTION

Next: End

FUSE INV

WATER PRESSURE SWITCH

Next: End

FUSE INV NO LWPS

CABLE - CONNECTING - GAS SECTION - SIT

Next: End

NO DISPLAY

MAINS FUSE

Next: End

NO DISPLAY

SET - 10 OFF FUSES 2.0AT

Next: End

NO DISPLAY

SET - 10 FUSES 1.25AT

Next: End

NO DISPLAY

PCB

Next: End

EXTERNAL CONTROLS (VOLTAGE IN)

Next: End

PUMP RUNS (CH DEMAND)

SENSOR - NTC

Next: End

PUMP RUNS (CH DEMAND)

SENSOR - NTC

Next: End

BURNER MODULATION

SET - 3 KNOBS + LEVER (GREEN)

Next: End

HONEYWELL NO VOLTS TO GV R203 OK

CABLE - CONNECTING - GAS SECTION - HONEYWELL

Next: End

SETTING MULTIMETER TO DIODE

Z REDIRECT

Next: End

F20 FAULT CODE DHW OPERATION

HEAT EXCHANGER

Next: End

F20 FAULT CODE MINIMUM

GAS VALVE INLET PRESSURE

Next: End

F20 FAULT CODE MAXIMUM

GAS VALVE INLET PRESSURE

Next: End

F20 FAULT CODE CH OPERATION

AUTOMATIC BY-PASS

Next: End

ELECTRODE SPARKING

SWITCH - FAN PROVING - HUBA

Next: End

DHW FLOW RATE

VALVE 3/4IN X 15

Next: End

NO PRESSURE HAS LWPS

GAS VALVE AND PCB

Next: End

DHW DEMAND

AQUA SENSOR - IMPELLOR ONLY

Next: End

DHW DEMAND NO VOLTAGE TO AQUA SENSOR

PCB

Next: End

DHW MAXIMUM BURNER PRESSURE

GAS SECTION

Next: End

F20 FAULT CODE GAS MODULATION (DHW)

GAS SECTION

Next: End

F20 FAULT CODE GV MODUREG

CABLE TREE

Next: End

F20 FAULT CODE

KIT - JUMPER LINK

Next: End

GV MOD

CABLE TREE

Next: End

DHW MAXIMUM BURNER PRESSURE

SENSOR - NTC

Next: End

DHW MAXIMUM BURNER PRESSURE

KIT - JUMPER LINK

Next: End

DHW MAXIMUM BURNER PRESSURE

GAS VALVE INLET PRESSURE

Next: End

FUSE INV HONEYWELL HARNESS SHORT

GAS SECTION

Next: End

FUSE INV HONEYWELL HARNESS OK

GAS SECTION

Next: End

FUSE INV DIODE FAILURE

CABLE - CONNECTING - GAS SECTION - HONEYWELL

Next: End

R203 RESISTOR

GAS VALVE AND PCB

Next: End

NO PRESSURE SWITCH

PCB

Next: End

RESISTOR R203

GAS VALVE HARNESS AND PCB

Next: End

LOW PRESSURE

GAS VALVE ADJUSTMENT

Next: End

BURNER IGNITES SPARKING CONTINUES THEN BOILER LOCKS OUT

PCB

Next: End

BURNER ESTABLISHED

TUBE - DISTRIBUTOR (BURNER INJECTOR)

Next: End

FAN INDICATOR ILLUMINATED

PCB

Next: End

FAN INDICATOR ILLUMINATED

SWITCH - FAN PROVING - HUBA

Next: End

FAN INDICATOR FLASHING

FAN

Next: End

FAN INDICATOR FLASHING NO VOLTAGE TO APS

PCB

Next: End

FAN INDICATOR FLASHING RUNNING SLOW

FAN

Next: End

SCALED

HEAT EXCHANGER - SECONDARY

Next: End

FAN INDICATOR FLASHING - IGNORING APS

PCB

Next: End

SENSOR PRIMARY F0/F10 FAULT CODE

CABLE TREE

Next: End

F11/F1 FAULT CODE

PCB

Next: End

SENSOR TEMP RETURN F11/1 FAULT CODE

CABLE TREE

Next: End

DHW TOO HOT

GAS VALVE ADJUSTMENT

Next: End

DHW TOO HOT

PCB

Next: End

DHW NOISY OPERATION KETTLES

HEAT EXCHANGER - SECONDARY

Next: End

DHW OPERATION

HEAT EXCHANGER

Next: End

DHW OPERATION

VALVE - DIVERTER

Next: End

DHW COOL RADIATORS HOT

MOTOR - DIVERTER VALVE

Next: End

DHW COLD RADIATORS COLD

HEAT EXCHANGER - SECONDARY

Next: End

DHW OPERATION

FAN

Next: End

DHW MAXIMUM BURNER PRESSURE

FAN

Next: End

BOILER HEATS BUT RADS COLD

VALVE - DIVERTER

Next: End

BOILER HEATS BUT RADS COLD

Next: End

CH NOISY DHW OKAY

Next: End

BURNER MODULATION

GAS SECTION

Next: End

SYSTEM PRESSURE RISE

EXPANSION VESSEL 10 LITRE - SQUARE

Next: End

BURNER ESTABLISHED MECHANICAL

GAS SECTION

Next: End

BURNER DROPS OUT

SWITCH - FAN PROVING - HUBA

Next: End

PUMP RUNS (CH DEMAND)

Next: End

PUMP RUNS

PUMP ASSEMBLY - GRUNDFOS VP5

Next: End

PUMP RUNS

INTEGRAL HEATING CONTROLS

Next: End

CH OP

MOTOR - DIVERTER VALVE

Next: End

F20 FAULT CODE FLOW SENSOR

CABLE TREE

Next: End

F20 FAULT CODE RETURN SENSOR

CABLE TREE

Next: End

F20 FAULT CODE

HEAT EXCHANGER - SECONDARY

Next: End

F27 FAULT CODE

Z REDIRECT

Next: End

FAN RUNS (CH DEMAND)

SWITCH - FAN PROVING - HUBA

Next: End

F28 FAULT CODE

PCB

Next: End

F28 FAULT CODE

Z REDIRECT

Next: End

F27 FAULT CODE

PCB

Next: End

F60 FAULT CODE

PCB

Next: End

FAN RUNS (CH DEMAND)

FAN

Next: End

F20 NOT RUNNING

PUMP ASSEMBLY - GRUNDFOS VP5

Next: End

ELECTRODE SPARKING NO VOLTAGE TO APS

PCB

Next: End

ELECTRODE SPARKING

PCB

Next: End

NO PRESSURE SWITCH

GAS VALVE

Next: End

FUSE INVESTIGATION - FAN

CABLE TREE

Next: End

SIT VALVE

FUSE INVESTIGATION NO FAULT

Next: End

FUSE INV

HARNESS GAS VALVE AND WATER PRESSURE SWITCH

Next: End

NO BURNER PRESSURE NO LWPS

CABLE - CONNECTING - GAS SECTION - SIT

Next: End

NO DISPLAY

Next: End

MAINS FUSE

Z REDIRECT

Next: End

FUSE F1

Z REDIRECT

Next: End

FUSE F2

Z REDIRECT

Next: End

DISPLAY ILLUMINATES VOLTAGE TO DISPLAY

PCB

Next: End

NO DISPLAY

TRANSFORMER

Next: End

FLOW SENSOR

CABLE TREE

Next: End

PUMP RUNS (CH DEMAND)

PCB

Next: End

RETURN SENSOR

CABLE TREE

Next: End

BURNER MODULATION

PCB

Next: End

HONEYWELL MECHANICAL FAULT

GAS SECTION

Next: End

F20 FAULT CODE MINIMUM

GAS VALVE ADJUSTMENT

Next: End

F20 INVESTIGATION

OVERHEAT

Next: End

F20 FAULT DURING OP

PCB

Next: End

F20 FAULT CODE

Next: End

F20 FAULT CODE NOT SHUTTING DOWN

PCB

Next: End

ELECTRODE SPARKING RUNNING SLOW

FAN

Next: End

NO PRESSURE HAS LWPS

PCB

Next: End

DHW DEMAND

PCB

Next: End

DHW DEMAND

SENSOR - HALL

Next: End

F20 FAULT CODE - MODULATION VOLTAGE

PCB

Next: End

F20 FAULT CODE MAXIMUM

GAS VALVE ADJUSTMENT

Next: End

DHW MAXIMUM BURNER PRESSURE

PCB

Next: End

GAS MODULATION (DHW)

GAS SECTION

Next: End

FUSE INV HONEYWELL

CABLE - CONNECTING - GAS SECTION - HONEYWELL

Next: End

HONEYWELL GAS VALVE

FUSE INVESTIGATION NO FAULT

Next: End

HONEYWELL NO VOLTS R203 OK

PCB

Next: End

R203 RESISTER

GAS VALVE HARNESS AND PCB

Next: End

PRESSURE INCREASES BUT FLAME BAFFLES

CHARACTERISTIC TEST FROM DHW MAXIMUM BURNER PRESSURE

Next: p104

BURNER IGNITES WITH CORRECT BP BUT SPARKING CONTINUES AND BOILER LOCKS OUT

CHARACTERISTIC TEST FROM BURNER ESTABLISHED

Next: p1041

PRESSURE DOES NOT REACH MAXIMUM

CHARACTERISTIC TEST FROM DHW MAXIMUM BURNER PRESSURE

Next: p899

BURNER PRESSURE CORRECT, SPARKING PRESENT BUT BURNER FAILS TO IGNITE

CHARACTERISTIC TEST FROM BURNER ESTABLISHED

Next: p1051

VOLTAGE PRESENT ON TEST 1 BUT DOES NOT DROP

CHARACTERISTIC TEST FROM AIR PRESSURE SWITCH (AIR DETECT)

Next: p1083

VOLTAGE ABSENT ON TEST 1

CHARACTERISTIC TEST FROM AIR PRESSURE SWITCH (AIR DETECT)

Next: !p1085

BURNER BAFFLES OUT DURING OPERATION

CHARACTERISTIC TEST FROM DHW OPERATION

Next: p1113

TEMPERATURE RISE UNSATISFACTORY - RADIATORS REMAIN COOL WITH NO CH DEMAND

CHARACTERISTIC TEST FROM DHW OPERATION

Next: p1115

TEMPERATURE RISE UNSATISFACTORY - RADIATORS BEGIN TO HEAT WITH NO CH DEMAND

CHARACTERISTIC TEST FROM DHW OPERATION

Next: p1117

BOILER NOISY / KETTLING DURING OPERATION

CHARACTERISTIC TEST FROM DHW OPERATION

Next: p1119

DHW TOO HOT

CHARACTERISTIC TEST FROM DHW OPERATION

Next: p1121

CH NOISY, DHW OK

CHARACTERISTIC TEST FROM CENTRAL HEATING OPERATION

Next: p150

BOILER HEATS, BUT RADS COLD

CHARACTERISTIC TEST FROM CENTRAL HEATING OPERATION

Next: p152

EXCESSIVE SYSTEM PRESSURE RISE

CHARACTERISTIC TEST FROM CENTRAL HEATING OPERATION

Next: !p184

PRESSURE INCREASES BUT FLAME DROPS OUT THEN IMMEDIATELY RE-IGNITES

CHARACTERISTIC TEST FROM DHW MAXIMUM BURNER PRESSURE

Next: p310

VOLTAGE PRESENT ON TEST 1 BUT DOES NOT DROP

CHARACTERISTIC TEST FROM AIR PRESSURE SWITCH (AIR DETECT)

Next: p560

VOLTAGE ABSENT ON TEST 1

CHARACTERISTIC TEST FROM AIR PRESSURE SWITCH (AIR DETECT)

Next: !p559

BURNER PRESSURE PRESENT BUT BELOW MINIMUM

CHARACTERISTIC TEST FROM BURNER ESTABLISHED

Next: p578

ONLY MINIMUM PRESSURE IS INCORRECT

CHARACTERISTIC TEST FROM PRESSURE BURNER MAXIMUM AND MINIMUM

Next: p723

MAXIMUM PRESSURE INCORRECT OR BOTH MAX AND MIN INCORRECT

CHARACTERISTIC TEST FROM PRESSURE BURNER MAXIMUM AND MINIMUM

Next: p725

NO BURNER PRESSURE

CHARACTERISTIC TEST FROM BURNER ESTABLISHED

Next: p273

CH NOISY OPERATION / OVERHEATS OR CUTS OUT QUICKLY

CHARACTERISTIC TEST FROM TEMPERATURE CH OPERATION DIFFERENTIAL AND RUN TO MAX

Next: p776

DIFFERENTIAL OK BUT BOILER RETURNS TO FAULT CODE BEFORE REACHING TEMPERATURE

CHARACTERISTIC TEST FROM TEMPERATURE CH OPERATION DIFFERENTIAL AND RUN TO MAX

Next: !p768

DIFFERENTIAL OK BUT BOILER CONTINUES TO HEAT PAST 88°C

CHARACTERISTIC TEST FROM TEMPERATURE CH OPERATION DIFFERENTIAL AND RUN TO MAX

Next: !p780

25/05/2021 15:38:08 2105_1_50_1 14/07/2021 11:24:08

08/06/2021 06:22:15

Next: End

GAS VALVE RESISTANCE - SIT

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: !p1002, !f1003

AIR PRESSURE SWITCH (NORMALLY OPEN)

{GAINPCBACS}

Next: !p1062, f1065

APS TUBES CONDITION

LOCATE THE AIR PRESS

Next: p1066, !f1067

DOES THE FAN RUN

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p1080, f1074

FAN VOLTAGE

{GAINPCBACS}
ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p1075, !f1076

FLOW SENSOR HARNESS RESISTANCE

DISCONNECT CONNECTOR X2 FROM THE PCB

Next: p1103, f1104

FLOW STAT RESISTANCE

REMOVE THE CONNECTOR

Next: !p1105, !f1106

RETURN STAT RESISTANCE

REMOVE THE CONNECTOR FROM THE RETURN THERMOSTAT

Next: !p1109, !f1110

FLOW STAT RESISTANCE

REMOVE THE CONNECTOR

Next: p1124, !f1125

BY-PASS (INTERNAL) OPENS CORRECTLY

ENSURE THERE IS NO FLOW AROUND THE HEATING SYSTEM
I.E. TURN OFF ALL RADIATORS

Next: !p1132, !f1133

VOLTAGE DIVERTER MOTOR AT PCB

{GAINPCBACS}
DISC

Next: !p1136, !f1137

DIVERTER VALVE MOTOR OPERATION

REMOVE, BY UNSCREWING THE RETAINING RING,
THE DIVERTER VALVE MOTOR FROM THE DIVERTER VALVE

Next: !p161, f353

GAS VALVE MODULATION VOLTAGE (NO MODULATION)

{GAINPCBACS}
ON/OFF SWITCH IN THE ON POSITION

Next: !p175, f176

FLOW STAT RESISTANCE

REMOVE THE CONNECTOR

Next: p688, !f178

GAS VALVE VOLTAGE

{GAINPCBACS}
ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p276, f277

R203 RESISTANCE

{GAINPCBACS}

Next: !p994, f995

EXTERNAL CONTROLS (VOLTAGE OUT)

{GAINPCBACS}
EXTERNAL CONTROLS CALLING

Next: p322, f323

EXTERNAL CONTROLS (VOLTAGE IN)

{GAINPCBACS}

Next: !p324, !f674

DISCONNECT INTEGRAL CONTROLS

REMOVE THE INTEGRAL

Next: !p332, f678

VOLTAGE DIVERTER MOTOR AT PCB

{GAINPCBACS}
DISC

Next: !p354, !f359

AIR PRESSURE SWITCH (NORMALLY OPEN)

{GAINPCBACS}

Next: p41, f42

APS TUBES CONDITION

LOCATE THE AIR PRESS

Next: p43, !f44

FAULT CODE RESET

ENSURE BOILER IS COOL
ENSURE NO DEMAND

Next: p433, !f434

FLOW STAT RESISTANCE

REMOVE THE CONNECTOR

Next: !p441, !f442

RETURN STAT RESISTANCE

REMOVE THE CONNECTOR FROM THE RETURN THERMOSTAT

Next: !p445, !f446

TEMPERATURE CH OPERATION DIFFERENTIAL

ON/OFF SWITCH IN ON

Next: !p461, !f758

OBSERVATION BOILER RESET FALSE FLAME

ENSURE NO DEMAND

Next: !p467, f469

FLAME SENSE ELECTRODE WIRING HARNESS CONTINUITY

Next: p470, !f471

ELECTRODE SPARKING (FAULT CODE)

REMOVE COMBUSTION CHAMBER DOOR
ON/OFF SWITCH IN ON POSITION

Next: !p497, f492

ELECTRODE/LEAD RESISTANCE

REMOVE BOTH SPARK LEADS FROM THE PCB

Next: p493, !f494

INSPECTION WIRING HARNESS

{GAINPCBACS}

Next: p501, !f502

AIR PRESSURE SWITCH (AIR DETECT)

{GAINPCBACS}

Next: p572, ?556, ?558

PUMP VOLTAGE

ON/OFF SWITCH IN ON

Next: !p547, !f548

GAS VALVE VOLTAGE

{GAINPCBACS}
ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p599, f600

DHW ISOLATING VALVE

Next: p7, !f8

R203 RESISTANCE

{GAINPCBACS}

Next: !p1000, f1001

GAS VALVE RESISTANCE - SIT

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: !p644, !f606

GAS VALVE RESISTANCE - SIT

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: !p832, !f833

RESISTANCE TRANSFORMER

DISCONNECT CONNECTOR X3 FROM THE PCB

Next: p622, !f623

RESISTANCE FAN

GAIN ACCESS TO THE FAN
DISCONNECT THE WIRES FROM THE FAN MOTOR AND EARTH POINTS

Next: !p627, !f628

GAS VALVE RESISTANCE - SIT

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: p645, !f641

MAINS POWER SUPPLY

{GAINPCBACS}

Next: p653, f654

RESISTANCE FUSE MAINS

REMOVE THE FUSE FROM THE FUSED SPUR

Next: !p655, f656

FURTHER INVESTIGATION FUSE

Next: !p657, !f658

FURTHER INVESTIGATION FUSE

Next: !p661, !f662

FURTHER INVESTIGATION FUSE

Next: !p665, !f666

TRANSFORMER (VOLTAGE IN)

{GAINPCBACS}
ON/OFF SWITCH IN ON POSITION

Next: !p669, !f670

FLOW SENSOR HARNESS RESISTANCE

DISCONNECT CONNECTOR X2 FROM THE PCB

Next: p679, f680

FLOW STAT RESISTANCE

REMOVE THE CONNECTOR

Next: !p681, !f682

RETURN STAT RESISTANCE

REMOVE THE CONNECTOR FROM THE RETURN THERMOSTAT

Next: !p685, !f687

VOLTAGE PCB TO AQUA SENSOR (PERMANENT)

{GAINPCBACS}

Next: p842, !f847

INSPECTION IMPELLOR

DHW CIRCUIT DRAINED AND ISOLATED

Next: !p845, !f846

INSPECTION PCB JUMPER

{GAINPCBACS}

Next: !p949, !f950

FLOW STAT RESISTANCE

REMOVE THE CONNECTOR

Next: p959, !f960

DIODE GAS VALVE HARNESS

REMOVE THE GAS VALVE

Next: p974, !f981

GAS VALVE RESISTANCE - HONEYWELL

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: !p977, !f978

GAS VALVE RESISTANCE - HONEYWELL

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: !p996, !f997

HEAT EXCHANGER FLUE WAYS

REMOVE THE COMBUSTION CHAMBER FRONT PANEL

Next: p117, !f118

FLAME SENSE ELECTRODE WIRING HARNESS CONTINUITY

Next: p1042, !f1043

FLAME SENSE ELECTRODE CONDITION AND POSITION

DISCONNECT THE LEAD FROM THE FLAME SENSE ELECTRODE

Next: p1044, !f1045

INSPECTION BURNER

REMOVE THE BURNER ASSEMBLY

Next: p1046, !f1047

INSPECTION BURNER MANIFOLD

REMOVE BURNER MANIFOLD

Next: !p1048, !f1049

SPARK ELECTRODE GAP

REMOVE THE COMBUSTION CHAMBER FRONT PANEL.

Next: !p1052, !f1053

VENTURI BLOCKED

DISCONNECT BOTH AIR

Next: p1068, !f1069

FLUE CHECK

Next: !p1070, !f1071

FAN HARNESS RESISTANCE

Next: !p1077, !f1078

AIR PRESSURE SWITCH (AIR DETECT)

{GAINPCBACS}

Next: !p1101, ?1082, ?1084

APS TUBES CONDITION

LOCATE THE AIR PRESS

Next: p1086, !f1087

VENTURI BLOCKED

DISCONNECT BOTH AIR

Next: p1088, !f1089

FLUE CHECK

Next: p1090, !f1091

APS HARNESS RESISTANCE

GAIN ACCESS TO PCB
USE INSULATION MAT AS REQUIRED

Next: p1092, !f1093

RESISTANCE APS WITH KIT

REMOVE APS FROM BOILER (LOCATED TOP RIGHT BEHIND COMBUSTION CHAMBER)

Next: !p1094, !f1095

RETURN SENSOR HARNESS RESISTANCE

DISCONNECT CONNECTOR X2 FROM THE PCB

Next: !p1107, f1108

HEAT EXCHANGER FLUE WAYS

REMOVE THE COMBUSTION CHAMBER FRONT PANEL

Next: p1142, !f1143

PUMP LIMPET TEST

Next: p1138, !f1139

DIVERTER VALVE MOTOR OPERATION

REMOVE, BY UNSCREWING THE RETAINING RING,
THE DIVERTER VALVE MOTOR FROM THE DIVERTER VALVE

Next: !p1134, f1135

PUMP LIMPET TEST

Next: p1128, !f1129

GAS VALVE MODULATION VOLTAGE (NO MODULATION)

{GAINPCBACS}
ON/OFF SWITCH IN THE ON POSITION

Next: !p1122, f1123

INSPECTION DHW CONTROL KNOB

Next: !p1126, !f1127

CH OPERATION

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: !p1130, f1131

INSPECTION BURNER MANIFOLD

REMOVE BURNER MANIFOLD

Next: !p1140, !f1141

FLUE CHECK

Next: !p1144, !f1145

FLUE CHECK

Next: !p119, !f120

PUMP LIMPET TEST

Next: p167, !f168

DIVERTER VALVE OPERATION (CH)

ON/OFF SWITCH IN ON

Next: p159, f160

BY-PASS (INTERNAL)

ENSURE RADIATORS ARE OPEN AND THAT WATER CAN CIRCULATE AROUND THE SYSTEM

Next: !p165, !f166

BY-PASS (INTERNAL) OPENS CORRECTLY

ENSURE THERE IS NO FLOW AROUND THE HEATING SYSTEM
I.E. TURN OFF ALL RADIATORS

Next: !p169, !f170

GAS VALVE TYPE

Next: p274, f275

BOILER VERSION

LOCATION OF THE LOW WATER PRESSURE SWITCH IS JUST ABOVE THE PUMP, RIGHT-HAND SIDE OF THE BOILER

Next: p284, f598

GAS INLET PRESSURE

ON/OFF SWITCH IN ON

Next: p280, !f281

GAS VALVE RESISTANCE - HONEYWELL

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: p701, !f306

SYSTEM PRESSURE CHECK

Next: p294, !f295

GAS VALVE VOLTAGE

{GAINPCBACS}
ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p296, f609

GAS VALVE RESISTANCE - SIT

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: p298, !f593

GAS INLET PRESSURE

ON/OFF SWITCH IN ON

Next: p300, !f301

WATER PRESSURE SWITCH CONTINUITY

REMOVE THE COVER FRO

Next: p302, !f303

WATER PRESSURE SWITCH WIRING HARNESS RESISTANCE

REMOVE THE COVER FROM THE WATER PRESSURE SWITCH BY PULLING BACKWARDS ALONG THE WIRING

Next: !p304, !f305

HEAT EXCHANGER FLUE WAYS

REMOVE THE COMBUSTION CHAMBER FRONT PANEL

Next: p311, !f312

VENTURI BLOCKED

DISCONNECT BOTH AIR

Next: p313, !f314

FAN INSPECTION

Next: p315, !f316

APS TUBES CONDITION

LOCATE THE AIR PRESS

Next: p317, !f318

FLUE CHECK

Next: !p319, !f320

PUMP VOLTAGE

ON/OFF SWITCH IN ON

Next: !p330, f331

FAN VOLTAGE

{GAINPCBACS}
ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p49, !f50

VENTURI BLOCKED

DISCONNECT BOTH AIR

Next: p45, !f46

SYSTEM PRESSURE CHECK

Next: p524, !f436

PUMP LIMPET TEST

Next: p437, !f438

FLOW SENSOR HARNESS RESISTANCE

DISCONNECT CONNECTOR X2 FROM THE PCB

Next: p439, f440

RETURN SENSOR HARNESS RESISTANCE

DISCONNECT CONNECTOR X2 FROM THE PCB

Next: p706, f444

PUMP OVERRUN

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p451, !f448

FLUE CHECK

Next: !p47, !f48

TEMPERATURE DHW OPERATION DIFFERENTIAL

ON/OFF SWITCH IN ON

Next: p455, f460

TEMPERATURE CH OPERATION DIFFERENTIAL AND RUN TO MAX

ON/OFF SWITCH IN ON

Next: !p755, ?765, ?767, ?779

FLAME SENSE ELECTRODE CONDITION AND POSITION

DISCONNECT THE LEAD FROM THE FLAME SENSE ELECTRODE

Next: !p498, !f473

FAN HARNESS RESISTANCE

Next: !p51, !f52

SPARK ELECTRODE GAP

REMOVE THE COMBUSTION CHAMBER FRONT PANEL.

Next: !p495, !f496

OBSERVATION BOILER RESET INTERNAL FAULT

ENSURE NO DEMAND

Next: !p503, !f504

PUMP RUNS (CH DEMAND)

ON/OFF SWITCH IN ON POSITION
CH TEMP SELECTOR TO MAX
DHW TEMP SELECTOR TO MIN

Next: p435, f546

APS TUBES CONDITION

LOCATE THE AIR PRESS

Next: p561, !f562

VENTURI BLOCKED

DISCONNECT BOTH AIR

Next: p563, !f564

FLUE CHECK

Next: p567, !f566

APS HARNESS RESISTANCE

GAIN ACCESS TO PCB
USE INSULATION MAT AS REQUIRED

Next: p782, !f569

ELECTRODE/LEAD RESISTANCE

REMOVE BOTH SPARK LEADS FROM THE PCB

Next: p573, !f574

SPARK ELECTRODE GAP

REMOVE THE COMBUSTION CHAMBER FRONT PANEL.

Next: !p575, !f576

GAS INLET PRESSURE

ON/OFF SWITCH IN ON

Next: !p1005, !f1006

GAS VALVE RESISTANCE AND HARNESS

REMOVE CONNECTOR X14 FROM THE PCB

Next: p603, f604

GAS INLET PRESSURE

ON/OFF SWITCH IN ON

Next: !p607, !f608

RESISTANCE PUMP

DISCONNECT CONNECTOR X12 FROM THE PCB

Next: p624, !f625

RESISTANCE FAN AND HARNESS

DISCONNECT CONNECTOR X13 FROM THE PCB

Next: p629, f626

GAS VALVE TYPE

Next: p630, f965

GAS VALVE RESISTANCE AND HARNESS (SIT VALVE) - FUSE INV

REMOVE CONNECTOR X14 FROM THE PCB

Next: !p638, f639

WATER PRESSURE SWITCH CONTINUITY

REMOVE THE COVER FRO

Next: !p642, !f643

BOILER VERSION

LOCATION OF THE LOW WATER PRESSURE SWITCH IS JUST ABOVE THE PUMP, RIGHT-HAND SIDE OF THE BOILER

Next: p640, !f649

FUSE T2 RESISTANCE

REMOVE BLACK FUSE HOLDER T2 FROM THE PCB

Next: p659, f660

FUSE T1.25 RESISTANCE

REMOVE THE BROWN FUSE HOLDER T1.25 FROM THE PCB

Next: p663, f664

TRANSFORMER (VOLTAGE OUT)

{GAINPCBACS}
ON/OFF SWITCH IN ON POSITION
CH DEMAND OFF
DHW DEMAND OFF

Next: !p667, f668

RETURN SENSOR HARNESS RESISTANCE

DISCONNECT CONNECTOR X2 FROM THE PCB

Next: !p683, f684

INSPECTION DHW CONTROL KNOB

Next: !p689, !f691

FLOW LIMITER

ISOLATE THE DHW SUPPLY AND REMOVE THE DHW INLET

Next: p9, !f10

DIODE GAS VALVE HARNESS

REMOVE THE GAS VALVE

Next: !p702, !f703

PRESSURE BURNER MAXIMUM AND MINIMUM

DHW TEMPERATURE SELE

Next: p443, ?722, ?724

GAS INLET PRESSURE

ON/OFF SWITCH IN ON

Next: !p726, !f770

GAS INLET PRESSURE

ON/OFF SWITCH IN ON

Next: p926, !f772

BY-PASS (INTERNAL)

ENSURE RADIATORS ARE OPEN AND THAT WATER CAN CIRCULATE AROUND THE SYSTEM

Next: !p777, !f778

RESISTANCE APS WITH KIT

REMOVE APS FROM BOILER (LOCATED TOP RIGHT BEHIND COMBUSTION CHAMBER)

Next: !p783, !f784

PCB VOLTS DHW DEMAND

{GAINPCBACS}

Next: !p843, f844

GAS VALVE MODULATION RESISTANCE

DISCONNECT THE MODULATION SOLENOID CONNECTOR FROM THE GAS VALVE

Next: p952, !f901

DHW FILTER

MAINS WATER OFF
W

Next: !p11, !f12

GAS VALVE MODULATION RESISTANCE

DISCONNECT THE MODULATION SOLENOID CONNECTOR FROM THE GAS VALVE

Next: p943, !f927

GAS VALVE HARNESS RESISTANCE

REMOVE THE RED LEADS FROM THE MODULATION GAS VALVE

Next: p947, !f945

GAS VALVE MODULATION VOLTAGE

{GAINPCBACS}
ON/O

Next: !p951, f948

GAS VALVE HARNESS RESISTANCE

REMOVE THE RED LEADS FROM THE MODULATION GAS VALVE

Next: p956, !f954

GAS VALVE MODULATION VOLTAGE

{GAINPCBACS}
ON/O

Next: p957, f958

GAS INLET PRESSURE

ON/OFF SWITCH IN ON

Next: !p964, !f963

INSPECTION PCB JUMPER

{GAINPCBACS}

Next: !p961, !f962

RESISTANCE GAS VALVE AND HARNESS HONEYWELL FUSE INV

{GAINPCBACS}
DISCONNECT CONNECTOR X14 FROM THE PCB

Next: p975, f976

GAS VALVE RESISTANCE - HONEYWELL

DISCONNECT THE MAIN MULTI-PIN CONNECTOR FROM THE GAS VALVE

Next: !p979, !f980

Welcome to the XSol Diagnostic System