XSol Diagnostic System

WORCESTER 25 SI LPG

APPLIANCE APPEARS SATISFACTORY

RE-IGNITE DELAY

BOILER ON/OFF SWITCH ON

OVERRUN OPERATION

CH MODULATION

ATTACH U-GAUGE TO OUTLET PRESSURE TEST POINT ON GAS VALVE
CH TEMPERATURE SELECTOR SET TO MAX

EXCESSIVE SYSTEM PRESSURE RISE

CH TEMPERATURE SELECTOR SET TO MAX
ROOM THERMOSTAT (IF FITTED) CALLING

CENTRAL HEATING OPERATION

ROOM THERMOSTAT (IF FITTED) CALLING

DHW MODULATION

BOILER ON/OFF SWITCH

DHW OPERATION

BOILER ON/OFF SWITCH OFF
DHW TEMPERATURE SET TO MAX

AUTOMATIC FROST PROTECTION

CH TEMPERATURE SELECTOR IN OFF POSITION
DHW TEMPERATURE SELECTOR IN MIN POSITION

GAS VALVE SOUNDNESS

CH BURNER IGNITES

CH TEMPERATURE SELEC

DHW HIGH FLAME

BOILER ON/OFF SWITCH

DHW LOW FLAME

ATTACH U-GAUGE TO GA

DHW BURNER ESTABLISHED (FLAME SENSE)

BOILER ON/OFF SWITCH OFF

DHW BURNER IGNITES

BOILER ON/OFF SWITCH OFF

DHW SPARKING

BOILER ON/OFF SWITCH OFF

DHW FAN RUNS

BOILER ON/OFF SWITCH OFF

DHW DEMAND

DHW FLOW RATE

WORCESTER 25SI LPG

CH PUMP RUNS

BOILER ON/OFF SWITCH OFF
CH THERMOSTAT TO MAX POSITION
REMOVE PUMP VENT SCREW AS NECESSARY

TYPE OF DIAGNOSTIC PROCEDURE

PLEASE SELECT FROM O

FAIL POINT A

Next: &nff, f411

FAIL POINT B

Next: &nff, f423

FAIL POINT C

Next: &nff, f431

FAIL POINT D

Next: &nff, f435

FAIL POINT E

Next: &nff, f451

FAIL POINT F

Next: &nff, f465

FAIL POINT G

Next: &nff, f650

FAIL POINT H - LINK TO DHW SPARKING

Next: &nff, !f512

FAULT CODES

Next: &nff, !f514

FAIL POINT I

Next: &nff, f550

FAIL POINT J

Next: &nff, f560

FAIL POINT K & L

Next: &nff, f590

GAS VALVE SOUNDNESS

GAS VALVE

Next: End

EXCESSIVE SYSTEM PRESSURE RISE

EXPANSION VESSEL

Next: End

OVERRUN OPERATION

PCB

Next: End

RE-IGNITION DELAY

PCB

Next: End

CH BURNER IGNITES

MICROSWITCH - PRETTL

Next: End

DHW FAN RUNS

MICROSWITCH - PRETTL

Next: End

DHW FAN RUNS

KIT - THERMISTOR - SENSOR

Next: End

DHW FAN RUNS

FUSE F1 (2 AMP)

Next: End

DHW FAN RUNS

FUSE F2 (1.6 AMP)

Next: End

BURNER IGNITES BUT PRESSURE IS LOW

GAS INLET SUPPLY

Next: End

DHW FAN RUNS

TRANSFORMER

Next: End

DHW DEMAND

WATER VALVE - FLOW SWITCH

Next: End

DHW FANS RUNS

TUBING

Next: End

DHW BURNER IGNITES

KIT - THERMISTOR - SENSOR

Next: End

DHW HIGH FLAME

KIT - THERMISTOR - SENSOR

Next: End

ELECTRICAL SAFETY CHECKS

ELECTRICAL CHECKS

Next: End

CH MODULATION

KIT - THERMISTOR SENSOR

Next: End

DHW FAN RUNS

VENTURI

Next: End

DHW BURNER IGNITES

GAS INLET SUPPLY

Next: End

DHW LOW FLAME

GAS INLET SUPPLY

Next: End

DHW MODULATION

KIT - THERMISTOR - SENSOR

Next: End

DHW FAN RUNS

KIT - THERMISTOR SENSOR

Next: End

FAN RUNS FOR 30 TO 35 SECONDS THEN STOPS

KIT - THERMISTOR SENSOR

Next: End

DHW BURNER IGNITES

KIT - THERMISTOR SENSOR

Next: End

DHW BURNER IGNITES OPERATING SOLENOID

GAS VALVE

Next: End

ELECTRICAL MODULATING SOLENOID

GAS VALVE

Next: End

CH SENSOR (HIGH)

KIT - THERMISTOR SENSOR

Next: End

DHW NOT HOT ENOUGH

BURNER INJECTOR

Next: End

DHW DOES NOT GET HOT ENOUGH

GAS INLET SUPPLY

Next: End

FAN RUNS FOR 40 SECONDS OR LONGER

THERMOSTAT 116 DEG C - SECURITY

Next: End

FAN RUNS FOR 40 SECONDS OR LONGER

KIT - THERMISTOR SENSOR

Next: End

DHW SPARKING

HARNESS - IGNITION

Next: End

DHW SPARKING

ELECTRODE - DOUBLE - VULCANO

Next: End

DHW DOES NOT ESTABLISH

GAS INLET SUPPLY

Next: End

DHW DOES NOT ESTABLISH

FLUE

Next: End

DHW DOES NOT ESTABLISH

HEAT EXCHANGER ASSEMBLY

Next: End

DHW DOES NOT ESTABLISH

GAS VALVE

Next: End

DHW DOES NOT ESTABLISH

BURNER

Next: End

DHW DOES NOT ESTABLISH

SET - ELECTRODES

Next: End

AUTO FROST PCB

KIT - THERMISTOR SENSOR

Next: End

DOES NOT ESTABLISH LOW PRESSURE

GAS INLET SUPPLY

Next: End

DHW FLOW RATE

WATER VALVE - DHW FLOW ADJUSTER

Next: End

DHW FLOW RATE

FILTER - WATER - PRETTL

Next: End

DHW FLOW RATE

WATER SUPPLY

Next: End

CENTRAL HEATING OPERATION

PIPE ASSEMBLY - BYPASS

Next: End

CENTRAL HEATING OPERATION

MICROSWITCH - PRETTL

Next: End

CH PUMP RUNS

KIT - THERMISTOR SENSOR

Next: End

NO POWER TO ROOM STAT

PCB

Next: End

CH OPERATION SYSTEM NOT HEATING

PUMP

Next: End

DHW BURNER ESTABLISHES

HARNESS - FLAME SENSE ELECTRODE

Next: End

CH OPERATION NOISY

PUMP

Next: End

TYPE OF DIAGNOTIC PROCEDURE

Z REDIRECT

Next: End

FAIL POINT A

FUSE F1 (2 AMP)

Next: End

FAIL POINT A

Next: End

FAIL POINT B

FUSE F2 (1.6 AMP)

Next: End

FAIL POINT B

TRANSFORMER

Next: End

FAIL POINT C

PCB

Next: End

FAIL POINT D - NEON FAULTY

PCB

Next: End

FAIL POINT E - NEON FAULTY

PCB

Next: End

FAIL POINT F

FROST PROTECTION

Next: End

FAIL POINT F

KIT - THERMISTOR SENSOR

Next: End

FAIL POINT H

Z REDIRECT

Next: End

FAULT CODES

Z REDIRECT

Next: End

DHW FAN RUNS

Next: End

FAIL POINT E

MICROSWITCH - PRETTL

Next: End

FAIL POINT E

WATER VALVE - FLOW SWITCH

Next: End

FAIL POINT I

KIT - THERMISTOR SENSOR

Next: End

FAIL POINT I

KIT - THERMISTOR - SENSOR

Next: End

FAIL POINT J - NO POWER TO FAN

PCB

Next: End

FAN RUNS FOR 30 TO 35 SECONDS THEN STOPS

THERMOSTAT 116 DEG C - SECURITY

Next: End

FAIL POINT K

Z REDIRECT

Next: End

FAIL POINT J - SHORTING APS

TUBING

Next: End

FAIL POINT J - SHORTING APS

VENTURI

Next: End

DHW BURNER ESTABLISHED - BAFFLES

BURNER

Next: End

FAIL POINT D - NO VOLTAGE TO EXT CONTROLS

PCB

Next: End

BURNER DOES NOT IGNITE OR IGNITES AND DOES NOT RAMP-UP

PCB

Next: End

FAIL POINT D - IGNORING CH DEMAND

PCB

Next: End

CH PUMP RUNS - NO TIMER

PCB

Next: End

FAIL POINT D - NO TIMER

PCB

Next: End

FAIL POINT G - NO POWER TO PUMP

PCB

Next: End

FAIL POINT G - RUNNING SLOW

PUMP

Next: End

FAIL POINT G

GAS INLET SUPPLY

Next: End

FAIL POINT G

GAS VALVE

Next: End

FAIL POINT G

PCB ADJUSTMENT

Next: End

FAIL POINT GDHW DOES NOT GET HOT ENOUGH

GAS INLET SUPPLY

Next: End

FAIL POINT GDHW NOT HOT ENOUGH

BURNER INJECTOR

Next: End

FAIL POINT G - NO PUMP OVERRUN

PCB

Next: End

FAIL POINT G - OPEN CIRCUIT

THERMOSTAT 116 DEG C - SECURITY

Next: End

FAIL POINT GCENTRAL HEATING OPERATION

PIPE ASSEMBLY - BYPASS

Next: End

FAIL POINT G

KIT - THERMISTOR SENSOR

Next: End

FAIL POINT G

KIT - THERMISTOR - SENSOR

Next: End

DHW SPARKING

TUBING

Next: End

DHW SPARKING

VENTURI

Next: End

DHW SPARKING

FLUE

Next: End

DHW SPARKING

PRESSURE SWITCH - AIR

Next: End

FLAME DIES OR BAFFLES

GAS INLET SUPPLY

Next: End

FAILING TEST KIT DROPING OUT ON HIGH FLAME

PRESSURE SWITCH - AIR

Next: End

FAIL POINT J - APS NOT SWITCHING DROPING OUT ON HIGH FLAME

TUBING

Next: End

FAIL POINT J - APS NOT SWITCHING DROPING OUT ON HIGH FLAME

VENTURI

Next: End

FAIL POINT J DROPING OUT ON HIGH FLAME

FLUE

Next: End

RESTRICTED FLUEWAYS CAUSING BAFFLING

HEAT EXCHANGER ASSEMBLY

Next: End

FAILING TEST KIT

PRESSURE SWITCH - AIR

Next: End

FAIL POINT J - APS NOT SWITCHING

TUBING

Next: End

FAIL POINT J - APS NOT SWITCHING

VENTURI

Next: End

FAIL POINT J

FLUE

Next: End

DHW LOW FLAME

GAS VALVE

Next: End

DHW MODULATION

PCB

Next: End

BURNER IGNITES AT FULL PRESSURE

PCB

Next: End

DHW DOES NOT GET HOT ENOUGH

HEAT EXCHANGER ASSEMBLY

Next: End

DHW HIGH FLAME

PCB

Next: End

FUSE F2 (1,6 AMP)

PCB

Next: End

DHW BURNER IGNITES

BURNER INJECTOR

Next: End

DHW FAN RUNS

PRESSURE SWITCH - AIR

Next: End

DHW LOW FLAME

FLUE

Next: End

CH MODULATION

PCB

Next: End

DHW FAN RUNS

PCB

Next: End

BURNER PRESSURE (GAS PRESENT)

GAS VALVE

Next: End

DHW NOISY OPERATION

HEAT EXCHANGER ASSEMBLY

Next: End

MECHANICAL MODULATING SOLENOID

GAS VALVE

Next: End

PCB (LOCKOUT RESET)

PCB (LOCKOUT RESET)

Next: End

DHW SPARKING

PCB

Next: End

DHW DOES NOT ESTABLISH

PCB

Next: End

FROST PROTECTION

PCB

Next: End

DHW DOES NOT ESTABLISH

GAS VALVE ADJUSTMENT

Next: End

DHW FLOW RATE

HEAT EXCHANGER ASSEMBLY

Next: End

CH NOISY OPERATION, DHW OPERATION SATISFACTORY

SYSTEM RESTRICTIONS

Next: End

CENTRAL HEATING OPERATION

PUMP

Next: End

DHW FAN RUNS

FAN ASSEMBLY

Next: End

CH BURNER IGNITES

Next: End

PCB (ON/OFF SWITCH)

PCB

Next: End

CENTRAL HEATING OPERATION

SYSTEM RESTRICTIONS

Next: End

FAIL POINT A

PCB

Next: End

FAIL POINT B

PCB

Next: End

FAIL POINT C

Z REDIRECT

Next: End

FAIL POINT D

Z REDIRECT

Next: End

FAIL POINT E

PCB

Next: End

FAIL POINT E

Z REDIRECT

Next: End

FAIL POINT F

PCB

Next: End

TRANSFORMER VOLTAGE (OUTPUT)

PCB

Next: End

FAIL POINT I

PCB

Next: End

FAIL POINT J - NOT RUNNING

FAN ASSEMBLY

Next: End

FAIL POINT K

PCB

Next: End

FAIL POINT J - SHORTED

PRESSURE SWITCH - AIR

Next: End

NOT ESTABLISHING BAFFLES OUT

GAS VALVE

Next: End

FAIL POINT D

Next: End

CH PUMP RUNS

PROGRAMMER

Next: End

FAIL POINT D

PROGRAMMER

Next: End

FAIL POINT G

PRESSURE GAUGE

Next: End

FAIL POINT G

SYSTEM PRESSURE

Next: End

FAIL POINT G - NOT RUNNING

PUMP

Next: End

FAIL POINT G

GAS VALVE ADJUSTMENT

Next: End

FAIL POINT GDHW NOISY OPERATION

HEAT EXCHANGER ASSEMBLY

Next: End

FAIL POINT GDHW DOES NOT GET HOT ENOUGH

HEAT EXCHANGER ASSEMBLY

Next: End

FAIL POINT G CENTRAL HEATING OPERATION

SYSTEM RESTRICTIONS

Next: End

FAIL POINT G

THERMOSTAT 116 DEG C - SECURITY

Next: End

FAIL POINT G - NOT SHUTTING DOWN

PCB

Next: End

NO FAULT FOUND

OVERHEAT

Next: End

FAIL POINT G - STUCK IN FAULT

PCB

Next: End

FAIL POINT G CH NOISY OPERATION DHW OPERATION SATISFACTORY

SYSTEM RESTRICTIONS

Next: End

GAS VALVE 24 VOLT SUPPLY

PCB

Next: End

DIRTY

FAN ASSEMBLY

Next: End

DIRTY OR RUNNING SLOW DROPPING OUT ON HIGH FLAME

FAN ASSEMBLY

Next: End

FAIL POINT J - RUNNING SLOW

FAN ASSEMBLY

Next: End

BURNER IGNITES AT FULL PRESSURE

CHARACTERISTIC TEST FROM DHW LOW FLAME

Next: !p101

FLAME DIES OUT OR BAFFLES

CHARACTERISTIC TEST FROM DHW HIGH FLAME

Next: p830

BURNER IGNITES, BUT BURNER PRESSURE IS LOW

CHARACTERISTIC TEST FROM DHW HIGH FLAME

Next: p105

BURNER IGNITES AT FULL PRESSURE

CHARACTERISTIC TEST FROM DHW LOW FLAME

Next: p107

BURNER IGNITES BUT DOES NOT RAMP-UP

CHARACTERISTIC TEST FROM CH BURNER IGNITES

Next: p109

DHW DOES NOT GET HOT ENOUGH

CHARACTERISTIC TEST FROM DHW OPERATION

Next: p115

DHW NOISY OPERATION

CHARACTERISTIC TEST FROM DHW OPERATION

Next: !p295

RADIATORS HEAT UP BUT HEAT EXCHANGER NOISY (KETTLES)

CHARACTERISTIC TEST FROM CENTRAL HEATING OPERATION

Next: p402

SYSTEM DOES NOT HEAT, BUT BOILER REACHES TEMPERATURE

CHARACTERISTIC TEST FROM CENTRAL HEATING OPERATION

Next: p398

IGNITION PRESSURE LOW

CHARACTERISTIC TEST FROM PRESSURE IGNITION

Next: p328

PRESSURE AS ABOVE AND INCREASES BEFORE CUTTING OUT

CHARACTERISTIC TEST FROM PRESSURE IGNITION

Next: p330

FAN RUNS FOR 30 TO 35 SECONDS THEN STOPS

CHARACTERISTIC TEST FROM DHW SPARKING

Next: p52

FAN RUNS FOR 40 SECONDS OR LONGER

CHARACTERISTIC TEST FROM DHW SPARKING

Next: p306

PRESSURE READS CORRECTLY BUT DOES NOT INCREASE

CHARACTERISTIC TEST FROM INSPECTION PRESSURE SYSTEM

Next: !p706

SYSTEM PRESSURE LOW

CHARACTERISTIC TEST FROM INSPECTION PRESSURE SYSTEM

Next: !p708

DHW DOES NOT GET HOT ENOUGH

CHARACTERISTIC TEST FROM DHW OPERATION

Next: p726

DHW NOISY OPERATION

CHARACTERISTIC TEST FROM DHW OPERATION

Next: !p728

RADIATORS HEAT UP BUT HEAT EXCHANGER NOISY (KETTLES)

CHARACTERISTIC TEST FROM CENTRAL HEATING OPERATION

Next: p759

SYSTEM DOES NOT HEAT, BUT BOILER REACHES TEMPERATURE

CHARACTERISTIC TEST FROM CENTRAL HEATING OPERATION

Next: !p738

RETURNS TO OVERHEAT FAULT CODE BEFORE 82°C

CHARACTERISTIC TEST FROM OBSERVATION RUN BOILER UP TO TEMPERATURE

Next: !p748

FLOW TEMPERATURE ABOVE 88°C AND BOILER DOES NOT SHUT DOWN

CHARACTERISTIC TEST FROM OBSERVATION RUN BOILER UP TO TEMPERATURE

Next: !p750

BURNER IGNITES, BUT FLAME DIES OUT OR BAFFLES

CHARACTERISTIC TEST FROM DHW LOW FLAME

Next: p99

14/01/2020 15:01:18 2002_1_50_1 06/02/2020 11:51:15

16/01/2020 13:00:55

Next: End

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: !p358, !f359

DHW SENSOR

DISCONNECT YELLOW WIRES FROM DHW SENSOR
ENSURE DHW IS COOL

Next: !p120, !f258

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: !p285, !f211

DHW SENSOR

DISCONNECT YELLOW WIRES FROM DHW SENSOR
ENSURE DHW IS COOL

Next: p170, !f207

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: !p293, !f238

TRANSFORMER VOLTAGE (OUTPUT)

{GAINPCBACS}

Next: p31, f30

ON/OFF SWITCH VOLTAGE (OUTPUT)

Next: p33, f32

FUSE F1 (2 AMP)

REMOVE FUSE F1 FROM PCB

Next: p179, !f178

PRESSURE IGNITION

ATTACH U-GAUGE TO GAS VALVE OUTLET PRESSURE TEST POINT

Next: p326, ?327, ?329

AIR PRESSURE SWITCH TUBES

Next: p37, !f204

OBSERVATION WATER SUPPLY TO BOILER

Next: p363, !f368

FLOW SWITCH MICROSWITCH (RESISTANCE)

DISCONNECT PLUG CONNECTOR (MARKED ST16) FROM PCB

Next: p43, !f176

PUMP VOLTAGE

REMOVE ELECTRICAL COVER FROM PUMP

Next: !p385, f386

FLOW SWITCH MICROSWITCH (OPEN CIRCUIT)

DISCONNECT PLUG CONNECTOR (MARKED ST16) FROM PCB

Next: p389, !f388

VOLTAGE FROM BOILER TO EXTERNAL CONTROLS

Next: !p395, !f396

FUSE F1 (2 AMP) (FAULT CODE)

REMOVE FUSE F1 FROM PCB

Next: p412, !f413

FUSE F2 (1.6 AMP) (FAULT CODE)

REMOVE FUSE F2 FROM PCB

Next: p424, !f425

INFORMATION FAIL POINT C

Next: !p432, !f433

OBSERVATION DOES BOILER RESPOND TO CH DEMAND

BOILER ON/OFF SWITCH OFF
CH THERMOSTAT TO MAX POSITION
REMOVE PUMP VENT SCREW AS NECESSARY

Next: p436, f437

VOLTAGE FROM EXTERNAL CONTROLS TO BOILER

{GAINPCBACS}

Next: p645, f631

OBSERVATION DOES BOILER RESPOND TO DHW DEMAND

BOILER ON/OFF SWITCH OFF

Next: p452, f453

DHW DEMAND

Next: p454, !f517

TEMPERATURE AMBIENT

Next: p466, !f467

CH SENSOR (FAULT CODE)

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: p551, !f552

OBSERVATION DOES FAN RUN BEFORE LOCKOUT

BOILER ON/OFF SWITCH ON

Next: p843, f562

AIR PRESSURE SWITCH (OPEN CIRCUIT)

REMOVE GREEN WIRES FROM AIR PRESSURE SWITCH

Next: p563, f596

INFORMATION FAIL POINT K & L

FAULT CODES NOT

Next: !p591, !f592

AIR PRESSURE SWITCH TUBES

Next: p597, !f598

VOLTAGE FROM BOILER TO EXTERNAL CONTROLS

Next: !p632, !f633

OBSERVATION BOILER RESET (OVERHEAT)

ENSURE BOILER IS COOL

Next: p703, f755

PUMP VOLTAGE

REMOVE ELECTRICAL COVER FROM PUMP

Next: !p711, !f712

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: p717, !f718

OVERHEAT THERMOSTAT RESISTANCE

DISCONNECT ORANGE WIRES FROM OVERHEAT THERMOSTAT

Next: !p758, !f757

MAIN GAS VALVE VOLTAGE

REMOVE CONNECTORS (O

Next: p217, f77

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: p80, !f264

AIR PRESSURE SWITCH TUBES

Next: p822, !f823

FULL VOLTAGE MODULATING SOLENOID

REMOVE CONNECTOR (BL

Next: p164, f163

FLOW SWITCH MICROSWITCH (OPEN CIRCUIT)

DISCONNECT PLUG CONNECTOR (MARKED ST16) FROM PCB

Next: !p142, !f141

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: !p397, !f299

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: p152, !f303

INSPECTION BURNER INJECTOR

REMOVE BURNER ASSEMBLY

Next: !p154, !f302

MODULATING SOLENOID RESISTANCE

DISCONNECT PLUG CONNECTOR (MARKED ST16) FROM PCB

Next: !p298, !f297

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: !p196, !f195

MAINS POWER

BOILER ON/OFF SWITCH OFF

Next: !p289, !f515

TRANSFORMER RESISTANCE

REMOVE TRANSFORMER F

Next: !p199, !f200

MAIN GAS VALVE SOLENOID RESISTANCE

DISCONNECT PLUG CONNECTOR (MARKED ST16) FROM PCB

Next: p218, !f296

BURNER PRESSURE (GAS PRESENT)

BOILER ON/OFF SWITCH OFF
ATTACH U-GAUGE TO GAS VALVE OUTLET PRESSURE TEST POINT

Next: !p227, f228

OVERHEAT THERMOSTAT RESISTANCE

DISCONNECT ORANGE WIRES FROM OVERHEAT THERMOSTAT

Next: p307, !f308

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: p309, !f310

SPARK ELECTRODE LEADS

Next: p311, !f312

AIR PRESSURE SWITCH (OPEN CIRCUIT)

REMOVE GREEN WIRES FROM AIR PRESSURE SWITCH

Next: p35, f34

SPARK ELECTRODES

Next: !p313, !f314

FLAME SENSE ELECTRODE

Next: p369, !f352

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: p337, !f361

FUSE F2 (1.6 AMP)

REMOVE FUSE F2 FROM PCB

Next: p198, !f180

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: p331, !f345

INSPECTION FLUE

Next: p333, !f346

INSPECTION HEAT EXCHANGER

INSPECT THE HEAT EXCHANGER FLUEWAYS FOR RESTRICTIONS OR BLOCKAGES.

Next: p628, !f347

ADJUSTMENT IGNITION PRESSURE

ATTACH U-GAUGE TO GA

Next: !p360, !f348

INSPECTION BURNER ASSEMBLY

REMOVE THE BURNER ASSEMBLY FROM THE APPLIANCE

Next: !p351, !f350

FAN VOLTAGE

BOILER ON/OFF SWITCH OFF

Next: !p39, f38

DHW FLOW ADJUSTER

Next: p364, !f365

DHW INLET FILTER

BOILER DRAINED AND DISCHARGED
WATER OFF

Next: !p366, !f367

RESISTANCE HARNESS FLAME SENSE ELECTRODE

DISCONNECT FLAME SENSE LEAD FROM THE ELECTRODE
DISCONNECT PLUG ST16 FROM THE PCB

Next: p341, !f401

VENTURI (AIR DETECT)

Next: !p235, !f236

BY-PASS CHECK

DISCHARGE AND DRAIN BOILER

Next: !p381, !f382

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: p392, !f391

VOLTAGE FROM EXTERNAL CONTROLS TO BOILER

{GAINPCBACS}

Next: p640, f394

PUMP LIMPET TEST

Next: !p399, !f400

PUMP LIMPET TEST

Next: p380, !f406

MAINS POWER

BOILER ON/OFF SWITCH OFF

Next: !p416, !f417

TRANSFORMER RESISTANCE

REMOVE TRANSFORMER F

Next: !p428, !f429

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: p45, !f260

INFORMATION FAIL POINT D

Next: !p440, !f441

DHW SENSOR

DISCONNECT YELLOW WIRES FROM DHW SENSOR
ENSURE DHW IS COOL

Next: !p47, !f177

INFORMATION FAIL POINT E

Next: !p462, !f463

FLOW SWITCH MICROSWITCH (RESISTANCE)

DISCONNECT PLUG CONNECTOR (MARKED ST16) FROM PCB

Next: !p458, !f516

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: !p468, !f469

AIR PRESSURE SWITCH (AIR DETECT)

BOILER ON/OFF SWITCH

Next: p56, f821

DHW SENSOR

DISCONNECT YELLOW WIRES FROM DHW SENSOR
ENSURE DHW IS COOL

Next: !p555, !f556

OVERHEAT THERMOSTAT RESISTANCE

DISCONNECT ORANGE WIRES FROM OVERHEAT THERMOSTAT

Next: p60, !f59

FAN VOLTAGE

BOILER ON/OFF SWITCH OFF

Next: !p571, !f572

VENTURI (AIR DETECT)

Next: !p599, !f600

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: !p305, !f262

INSPECTION BURNER ASSEMBLY

REMOVE THE BURNER ASSEMBLY FROM THE APPLIANCE

Next: !p629, !f630

OBSERVATION DISCONNECT INTERNAL TIMER

UNPLUG INTERNAL TIME

Next: !p635, !f636

OBSERVATION DISCONNECT INTERNAL TIMER

UNPLUG INTERNAL TIME

Next: !p638, !f639

OBSERVATION IS INTERNAL TIMER FITTED

Next: p634, !f644

OBSERVATION IS INTERNAL TIMER FITTED

Next: p637, !f649

INSPECTION PRESSURE SYSTEM

Next: p704, ?705, ?707

CH PUMP RUNS

BOILER ON/OFF SWITCH OFF
CH THERMOSTAT TO MAX POSITION
REMOVE PUMP VENT SCREW AS NECESSARY

Next: p709, f710

PUMP LIMPET TEST

Next: p713, !f714

PRESSURE BURNER MAX AND MIN

ATTACH U-GAUGE TO GA

Next: p715, f716

PRESSURE BURNER CH MODE

CH TEMPERATURE SELEC

Next: p763, !f722

ADJUSTMENT PRESSURE MIN AND MAX

ATTACH U-GAUGE TO GA

Next: !p719, !f720

DHW OPERATION

BOILER ON/OFF SWITCH OFF
DHW TEMPERATURE SET TO MAX

Next: p723, ?725, ?727

CENTRAL HEATING OPERATION

ROOM THERMOSTAT (IF FITTED) CALLING

Next: p733, ?735, ?737

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: p729, !f730

INSPECTION BURNER INJECTOR

REMOVE BURNER ASSEMBLY

Next: !p731, !f732

OBSERVATION RUN BOILER UP TO TEMPERATURE

CH TEMPERATURE SELECTOR TO MAX
ATTACH TEMPERATURE CLAMP TO THE FLOW PIPE NEAR THE APS

Next: p745, ?747, ?749

OVERRUN OPERATION

Next: !p753, !f754

BY-PASS CHECK

DISCHARGE AND DRAIN BOILER

Next: !p760, !f761

CH SENSOR

REMOVE RED WIRES FROM CH TEMPERATURE SENSOR
ENSURE BOILER IS COOL

Next: p793, !f792

DHW SENSOR

DISCONNECT YELLOW WIRES FROM DHW SENSOR
ENSURE DHW IS COOL

Next: p721, !f820

DHW SENSOR

DISCONNECT YELLOW WIRES FROM DHW SENSOR
ENSURE DHW IS COOL

Next: !p82, !f206

VENTURI (AIR DETECT)

Next: p824, !f825

FLUE OPERATION

Next: p826, !f827

RESISTANCE APS WITH KIT

REMOVE THE WIRES AND

Next: !p828, !f829

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: p831, !f832

RESISTANCE APS WITH KIT

REMOVE THE WIRES AND

Next: p833, !f834

AIR PRESSURE SWITCH TUBES

Next: p835, !f836

VENTURI (AIR DETECT)

Next: p837, !f838

FLUE OPERATION

Next: p839, !f840

INSPECTION HEAT EXCHANGER

INSPECT THE HEAT EXCHANGER FLUEWAYS FOR RESTRICTIONS OR BLOCKAGES.

Next: !p841, !f842

RESISTANCE APS WITH KIT

REMOVE THE WIRES AND

Next: p844, !f845

AIR PRESSURE SWITCH TUBES

Next: p846, !f847

VENTURI (AIR DETECT)

Next: p848, !f849

FLUE OPERATION

Next: !p850, !f851

GAS INLET PRESSURE

ATTACH U-GAUGE TO INLET PRESSURE TEST POINT
GAS ON
BOILER ON/OFF SWITCH ON

Next: !p250, !f251

System Information

• Total Tests: 340
• Sequence Logic: Decoded from encrypted .seq file
• Navigation: Dynamic based on pass/fail results
• Source: 4731307 GW SWIFTFLOW 100 SIT Control