XSol Diagnostic System

Interactive Test Sequence Navigator

Welcome to the XSol Diagnostic System

This system provides interactive diagnostic tests with proper sequence navigation based on the decoded .seq file logic.

Start Diagnostic Sequence

or choose a specific test below:

NO FAULT FOUND

Next: nff

OBSERVATION DISPLAY OPERATION

ON OFF SWITCH ON (SWITCH FLUSH WITH THE FASCIA ON THE APPLIANCE)

Next: &655, f1280

DHW FLOW RATE

Next: &542, f104

OBSERVATION FAN RUNS

Next: &177, f1358

OBSERVATION BURNER IGNITION AND ESTABLISH

Next: &335, ?181, ?183, ?185, ?187

OPERATION DHW

DHW SET TO MAXIMUM T

Next: &444, ?278, ?280, ?282, ?284

FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

ATTACH A U GAUGE TO

Next: &277, ?370, ?372, ?1638

OPERATION CH

FLOW AND RETURN VALVES FULLY OPEN
CH THERMOSTAT SET TO MAX

Next: &495, ?438, ?440, ?442

OBSERVATION CH DEMAND RECOGNISED

BOILER CH THERMOSTAT SET TO MAX

Next: &437, f445

OBSERVATION SYSTEM PRESSURE RISE

BOILER CH THERMOSTAT TO MAX

Next: &499, f496

OBSERVATION CH RE FIRE DELAY

CENTRAL HEATING THER

Next: &501, !f500

OBSERVATION PREHEAT OPERATION

ENSURE APPLIANCE PRI

Next: &nff, ?503, ?505

OBSERVATION DHW DEMAND RECOGNISED

HOT WATER TAP ON WITH A FLOW RATE OF 3 L/MIN

Next: &554, f1494

OBSERVATION SELF CHECK

NO DEMANDS
ENSURE WARM START TURNED OFF
ENSURE CENTRAL HEATING TURNED OFF

Next: &607, ?659, ?661

HEADER FOR F75 FAULT CODE

Next: &nff, f1446

TYPE OF DIAGNOSTIC PROCEDURE

Next: &97, !f608

USER DISPLAY GUIDE

THE USER DISPLAY ON

Next: &556, !f656

HEADER FOR F22, F73, F74

INTENTIONALLY BLANK HEADER

Next: &nff, f697

HEADER FOR F00,F01,F10,F11,F64,F71,F85

INTENTIONALLY BLANK HEADER

Next: &nff, f708

F23, F24, F72, F83, F84

INTENTIONALLY BLANK HEADER

Next: &nff, f726

HEADER FOR F13

INTENTIONALLY BLANK HEADER

Next: &nff, f762

HEADER FOR F42, F70, F92

INTENTIONALLY BLANK HEADER

Next: &nff, f792

HEADER FOR F52, F53

INTENTIONALLY BLANK HEADER

Next: &nff, f802

HEADER FOR F26

INTENTIONALLY BLANK HEADER

Next: &nff, f820

HEADER FOR F25, F76

INTENTIONALLY BLANK HEADER

Next: &nff, f842

HEADER FOR F27, F62

INTENTIONALLY BLANK HEADER

Next: &nff, f850

HEADER FOR F32

INTENTIONALLY BLANK HEADER

Next: &nff, f1380

HEADER FOR F20

INTENTIONALLY BLANK HEADER

Next: &nff, f924

HEADER FOR F49

INTENTIONALLY BLANK HEADER

Next: &nff, f938

HEADER FOR F93

INTENTIONALLY BLANK HEADER

Next: &nff, f942

HEADER FOR F61

INTENTIONALLY BLANK HEADER

Next: &nff, f973

HEADER FOR FUSE INVESTIGATION

INTENTIONALLY BLANK HEADER

Next: &nff, f1400

HEADER FOR COMMUNICATION FAULT

INTENTIONALLY BLANK HEADER

Next: &nff, f1022

USER DISPLAY GUIDE

THE USER DISPLAY ON

Next: &nff, !f1031

HEADER FOR F77

NOT USED

Next: &nff, f1489

SETTING HEATING PARTIAL LOAD PARAMETER

1. PRESS THE

Next: &nff, !f1526

QUICK ACCESS DATA AND INFORMATION

THE TABLE BELOW SHOW

Next: &nff, !f1685

LITE DIAGNOSTIC

DIAGNOSIS RELIES ON

Next: &nff, !f1687

HEADER FOR QADAI FLOW THERMISTOR

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1689

HEADER FOR QADAI RETURN THERMISTOR

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1693

HEADER FOR QADAI HOT WATER THERMISTOR

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1697

HEADER FOR QADAI WARMSTART THERMISTOR

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1701

HEADER FOR QADAI GAS VALVE BOTTOM SOLENOID VOLTAGE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1705

HEADER FOR QADAI GAS VALVE TOP SOLENOID RESISTANCE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1709

HEADER FOR QADAI GAS VALVE BOTTOM SOLENOID RESISTANCE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1713

HEADER FOR QADAI GAS VALVE TOP SOLENOID VOLTAGE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1717

HEADER FOR QADAI GAS VALVE STEPPER MOTOR RESISTANCE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1721

HEADER FOR QUDAI PUMP RESISTANCE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1725

HEADER FOR QADAI DIVERTER VALVE RESISTANCE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1729

HEADER FOR QADAI DIVERTER VALVE VOLTAGE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1733

HEADER FOR QADAI DHW FLOW TURBINE

INTENTIONALLY BLANK - HEADER FOR QADAI

Next: &nff, f1737

SLOW OR WEAK

PUMP

Next: End

COMMUNICATION FAULT

PCB

Next: End

NO COMMUNICATION

CABLE - DISPLAY

Next: End

BLANK FOR FAULT CODES 2

Z DIRECTION CHOICE OR CONTINUE

Next: End

BLANK FOR USER DISPLAY GUIDE FOR PREHEAT

Z DIRECTION CHOICE OR CONTINUE

Next: End

FROST PROTECTION

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

FROST PROTECTION

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

FAULTY FROST PROTECTION

PCB

Next: End

OPERATION CORRECTLY

FROST PROTECTION

Next: End

BAFFLING OUT (BLOCKED)

PIPE - INLET - AIR

Next: End

RESISTANCE OUT OF RANGE

CODING RESISTOR GAS GROUP

Next: End

TO AIR MASS SENSORFAILS PT

HARNESS - WIRING (X20 AND X25)

Next: End

TO AIR MASS SENSORFAILS PT F93

HARNESS - WIRING (X20 AND X25)

Next: End

DHW TOO COOL RADS COLD EXCESSIVE DIFFERENTIAL

FILTER PRIMARY CIRCUIT

Next: End

EXCESSIVE DIFFERENTIAL AND TEMP RISE FAULT CODE

FILTER PRIMARY CIRCUIT

Next: End

BURNER BAFFLING

GAS INLET PRESSURE

Next: End

BOILER FIRING WITH NO DEMAND

SENSOR - NTC - FLOW (DHW SENSOR)

Next: End

DIVERTER VALVE MOTOR

HARNESS - WIRING (X2)

Next: End

DIVERTER VALVE MOTOR CH

HARNESS - WIRING (X2)

Next: End

BLANK FOR DSN SETTING

Z DIRECTION CHOICE OR CONTINUE

Next: End

POOR DHW FLOW

VALVE (DHW ISOLATOR)

Next: End

NOISY

PUMP

Next: End

NOISY CH

PUMP

Next: End

BOILER TO TEMP RADS COLD

PUMP

Next: End

TO AIR MASS SENSOR

HARNESS - WIRING (X20 AND X25)

Next: End

BAFFLING

BURNER

Next: End

BAFFLING

HEAT EXCHANGER PRIMARY

Next: End

BAFFLING

FLUE ASSEMBLY

Next: End

PERFORMANCE TEST FAIL

BURNER

Next: End

PERFORMANCE TEST FAIL

HEAT EXCHANGER PRIMARY

Next: End

PERFORMANCE TEST FAIL

FLUE ASSEMBLY

Next: End

PERFORMANCE TEST FAIL F93

BURNER

Next: End

PERFORMANCE TEST FAIL F93

HEAT EXCHANGER PRIMARY

Next: End

PERFORMANCE TEST FAIL F93

FLUE ASSEMBLY

Next: End

KETTLING ON DHW

FILTER PRIMARY CIRCUIT

Next: End

NOT ESTABLISHING

GAS INLET PRESSURE

Next: End

NOT RECTIFYING

CABLE - IGNITION (ELECTRODE LEAD)

Next: End

NOT RECTIFYING

ELECTRODE

Next: End

CAUSING NO RECTIFICATION

BURNER

Next: End

IGNITES BUT DOES NOT ESTABLISH

PIPE - INLET - AIR

Next: End

BLOWN STAND BY MODE AT POWER UP

FUSE (MAINS)

Next: End

HIGH FAN PRESSURE

PIPE - INLET - AIR

Next: End

RESTRICTED HIGH FAN PRESSURE

VENTURI AIR MASS SENSOR

Next: End

TO STEPPER MOTOR

HARNESS - WIRING (X20 AND X25)

Next: End

TO SOLENOIDS

HARNESS - WIRING (X20 AND X25)

Next: End

TO BOTTOM SOLENOID

HARNESS - WIRING (X20 AND X25)

Next: End

STOPPING BURNER LIGHTING

CODING RESISTOR GAS GROUP

Next: End

RESTRICTED FAN PRESSURE

CONDENSATE TRAP

Next: End

RESTRICTED FAN PRESSURE

BURNER

Next: End

RESTRICTED FAN PRESSURE

HEAT EXCHANGER PRIMARY

Next: End

SPARKING NOT LIGHTING

ELECTRODE

Next: End

SPARKING NOT LIGHTING

BURNER

Next: End

NO DEMAND TO FAN

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

NO DEMAND FOR FAN

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

FAN NOT RUNNING

SENSOR - NTC - FLOW (DHW SENSOR)

Next: End

DEMAND TO FAN

HARNESS - WIRING (X20 AND X25)

Next: End

NO DEMAND TO FAN 2

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

NO DEMAND FOR FAN 2

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

FAN NOT RUNNING 2

SENSOR - NTC - FLOW (DHW SENSOR)

Next: End

F32 FAULT CODE

HARNESS - WIRING (X20 AND X25)

Next: End

HALL SENSOR SIGNAL F32

FAN

Next: End

F32 NO DEMAND TO RUN FAN

PCB

Next: End

FUSE INVESTIGATION

PUMP

Next: End

DC HALL SENSORZ

HARNESS - WIRING (X20 AND X25)

Next: End

SPARKINGZ

CABLE - IGNITION (ELECTRODE LEAD)

Next: End

SPARKINGZ

ELECTRODE

Next: End

DC HALL SENSOR

HARNESS - WIRING (X20 AND X25)

Next: End

SPARKING

CABLE - IGNITION (ELECTRODE LEAD)

Next: End

SPARKING

ELECTRODE

Next: End

CH STAYING TOO COOL

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

CH STAYING TOO COOL

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

CH REMAINING TOO COOL

PCB

Next: End

FAULT CODE F75

SYSTEM PRESSURE

Next: End

FAULT CODE F75

PCB

Next: End

FAULT CODE F75

HARNESS - WIRING (X2)

Next: End

FAULT CODE F75

PUMP

Next: End

FAULT CODE F75 2

AIR VENT - AUTOMATIC

Next: End

FAULT CODE F75 2

EXPANSION VESSEL

Next: End

FAULT CODE F75 2

FILTER PRIMARY CIRCUIT

Next: End

NO POWER TO PUMP

PCB

Next: End

NO POWER TO PUMP 2

PCB

Next: End

PUMP PULSING

SYSTEM PRESSURE

Next: End

LOW WATER PRESSURE SWITCH

HARNESS - WIRING (X2)

Next: End

DOES NOT RUN

PUMP

Next: End

FAULT CODE F75

AIR VENT - AUTOMATIC

Next: End

FAULT CODE F75

EXPANSION VESSEL

Next: End

FAULT CODE F75

FILTER PRIMARY CIRCUIT

Next: End

FAULT CODE F77

CONDENSATE PUMP

Next: End

TO AQUA SENSOR3

HARNESS - WIRING (X2)

Next: End

NOT RECOGNISING DHW DEMAND3

SENSOR FITMENT

Next: End

OUT OF CAL STOPING DHW DEMAND RECOGNITION3

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

OUT OF CAL STOPPING DHW DEMAND RECOGNITION3

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

TO AQUA SENSOR

HARNESS - WIRING (X2)

Next: End

NOT RECOGNISING DHW DEMAND

SENSOR FITMENT

Next: End

OUT OF CAL STOPING DHW DEMAND RECOGNITION

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

OUT OF CAL STOPPING DHW DEMAND RECOGNITION

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

NOT RECOGNISING DEMAND

BURNER OFF LINK

Next: End

BLANK FOR PARTIAL LOAD PARAMETER

Z DIRECTION CHOICE OR CONTINUE

Next: End

NO 5V OR 22V LINE

PCB

Next: End

HARNESS SHORTED ANDDAMAGED PCB DBREF 13677 (3)

HARNESS - WIRING X20/X25 AND PCB

Next: End

HARNESS SHORTED AND DAMAGED PCB DBREF 13677 (2)

HARNESS - WIRING X20/X25 AND PCB

Next: End

HARNESS SHORTED AND DAMAGED PCB DBREF 13677

HARNESS - WIRING X20/X25 AND PCB

Next: End

HARNESS X2

HARNESS - WIRING (X2)

Next: End

PCB MAIN

PCB

Next: End

FUSE F1

FUSE F1

Next: End

BLANK DISPLAY AT STARTUP

HARNESS - WIRING (X20 AND X25)

Next: End

BAFFLING OUT (BLOCKED) DB REF 15027

PIPE - INLET - AIR

Next: End

BAFFLING DB REF 15027

CONDENSATE TRAP

Next: End

TO AIR MASS SENSOR DB REF 15027

HARNESS - WIRING (X20 AND X25)

Next: End

BAFFLING DB REF 15027

BURNER

Next: End

BAFFLING DB REF 15027

HEAT EXCHANGER PRIMARY

Next: End

BAFFLING DB REF 15027

FLUE ASSEMBLY

Next: End

BAFFLING OUT (BLOCKED) DB REF 15027 (2)

PIPE - INLET - AIR

Next: End

BAFFLING DB REF 15027 (2)

CONDENSATE TRAP

Next: End

TO AIR MASS SENSOR DB REF 15027 (2)

HARNESS - WIRING (X20 AND X25)

Next: End

BAFFLING DB REF 15027 (2)

BURNER

Next: End

BAFFLING DB REF 15027 (2)

HEAT EXCHANGER PRIMARY

Next: End

BAFFLING DB REF 15027 (2)

FLUE ASSEMBLY

Next: End

BLANK FOR TEST MODES INFORMATION

Z DIRECTION CHOICE OR CONTINUE

Next: End

BLANK FOR QADAI

Z DIRECTION CHOICE OR CONTINUE

Next: End

BLANK FOR LITE DIAGNOSTIC

Z DIRECTION CHOICE OR CONTINUE

Next: End

QADAI

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

QADAI

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

QADAI

SENSOR - NTC - FLOW (DHW SENSOR)

Next: End

QADAI

SENSOR - NTC - HEAT EXCHANGER (WARM START)

Next: End

QADAI TOP SOLENOID

GAS SECTION

Next: End

QADAI BOTTOM SOLENOID

GAS SECTION

Next: End

QADAI STEPPER MOTOR

GAS SECTION

Next: End

QADAI

PUMP

Next: End

QADAI

VALVE - DIVERTER - BRASS (MOTOR)

Next: End

QADAI

SENSOR - FLOW

Next: End

BURNER NOT IGNITING

GAS INLET PRESSURE

Next: End

BLANK FOR CASE OFF

Z DIRECTION CHOICE OR CONTINUE

Next: End

BAFFLING

CONDENSATE TRAP

Next: End

DHW OPERATION

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

DHW OPERATION

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

DHW TOO HOT

SENSOR - NTC - FLOW (DHW SENSOR)

Next: End

DHW TOO COOL

SENSOR - NTC - FLOW (DHW SENSOR)

Next: End

DHW TOO COOL

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

DHW TOO COOL

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

PERFORMANCE TEST FAIL

PIPE - INLET - AIR

Next: End

NO POWER TO 24V CONTROLS

PCB

Next: End

CH NOISY

FLOW AND RETURN VALVES

Next: End

SHUT CAUSING CH NOISE

BY-PASS

Next: End

TURNED OFF

FLOW AND RETURN VALVES

Next: End

FLAT

EXPANSION VESSEL

Next: End

CH DELAY FUNCTION

PCB

Next: End

BOILER NOT RECOGNISING FACILITY

SENSOR - NTC - HEAT EXCHANGER (WARM START)

Next: End

WARMSTART ISSUES

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

WARMSTART ISSUES

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

WARM START NOT HOT ENOUGH

SENSOR - NTC - HEAT EXCHANGER (WARM START)

Next: End

BLANK FOR TYPE OF PROCEDURE

Z DIRECTION CHOICE OR CONTINUE

Next: End

FOR USER DISPLAY GUIDE

Z DIRECTION CHOICE OR CONTINUE

Next: End

BLANK FOR FAULT CODES

Z DIRECTION CHOICE OR CONTINUE

Next: End

NOT OPENING TO RADS POSITION

VALVE - DIVERTER - BRASS

Next: End

F22 F73 F74

SYSTEM PRESSURE

Next: End

F22 F73 F74

HARNESS - WIRING (X2)

Next: End

F00 F01 F10 F11 F64 F71 F85

SENSOR FITMENT

Next: End

FAULT CODES

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

FAULT CODES

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

F23 F24 F83 F84

SYSTEM PRESSURE

Next: End

F23 F24 F83 F84

SENSOR FITMENT

Next: End

F23 F24 F83 F84

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

F23 F24 F83 F84

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

WEAK

PUMP

Next: End

F13

SENSOR - NTC - HEAT EXCHANGER (WARM START)

Next: End

CLOSED TOO MUCH OR BLOCKED

BY-PASS

Next: End

BLANK FOR PCBS REPLACED

Z DIRECTION CHOICE OR CONTINUE

Next: End

TO AIR MASS SENSOR F52, F53

HARNESS - WIRING (X20 AND X25)

Next: End

DISCONNECTED

VENTURI AIR MASS SENSOR CONNECTION

Next: End

TO STEPPER MOTOR F26

HARNESS - WIRING (X20 AND X25)

Next: End

F25 F76

HARNESS SAFETY FUSE

Next: End

PASSING SOLENOIDS

GAS SECTION

Next: End

F27 F62

ELECTRODE

Next: End

F20

CABLE - IGNITION (ELECTRODE LEAD)

Next: End

F20

ELECTRODE

Next: End

F20

SENSOR - NTC - CH FLOW/RETURN (FLOW)

Next: End

F20

SENSOR - NTC - CH FLOW/CH RETURN (RETURN)

Next: End

F49

PCB

Next: End

PERFORMANCE TEST FAIL F93

PIPE - INLET - AIR

Next: End

F61

HARNESS - WIRING (X20 AND X25)

Next: End

F61 (3)

HARNESS - WIRING (X20 AND X25)

Next: End

CODING RESISTOR OUTPUT

CODING RESISTOR OUTPUT

Next: End

F61 (2)

HARNESS - WIRING (X20 AND X25)

Next: End

NO COMMUNICATION

DISPLAY - PLUS

Next: End

BLANK FOR FAULT CODES 2 (2)

Z DIRECTION CHOICE OR CONTINUE

Next: End

TAP OPEN OR LEAKING DHW DRAW OFF

TAP OPEN OR LEAKING DHW DRAW OFF

Next: End

NO VOLTAGE AT RESTFAILS PT

VENTURI AIR MASS SENSOR

Next: End

NO VOLTAGE AT RESTFAILS PT F93

VENTURI AIR MASS SENSOR

Next: End

NOISY

HEAT EXCHANGER PRIMARY

Next: End

DHW TOO COOL

HEAT EXCHANGER PRIMARY

Next: End

DHW TOO COOL

HEAT EXCHANGER - DHW

Next: End

F23 F24 F83 F84

HEAT EXCHANGER - DHW

Next: End

HEAT EXCHANGER - DHW

HEAT EXCHANGER - DHW

Next: End

FLOW LIMITER

LIMITER (FLOW RESTRICTOR)

Next: End

BOILER FIRING WITH NO DEMAND

HARNESS - WIRING (X2)

Next: End

PASSING TO RADS

VALVE - DIVERTER - BRASS (MOTOR)

Next: End

PASSING TO RADS CH

VALVE - DIVERTER - BRASS (MOTOR)

Next: End

FILTER DHW

FILTER DHW

Next: End

NOT RESPONDING TO VARYING AIRFLOW

VENTURI AIR MASS SENSOR

Next: End

NO VOLTAGE AT REST

VENTURI AIR MASS SENSOR

Next: End

BAFFLING

GAS SECTION

Next: End

PERFORMANCE TEST FAIL

GAS SECTION

Next: End

PERFORMANCE TEST FAIL F93

GAS SECTION

Next: End

NOISY

HEAT EXCHANGER - DHW

Next: End

F42 F70 F90

PCB

Next: End

FURTHER INVESTIGATION MAINS

Z DIRECTION CHOICE OR CONTINUE

Next: End

STEPPER MOTOR

GAS SECTION

Next: End

TOP SOLENOID GONE

GAS SECTION

Next: End

BOTTOM SOLENOID NOT OPENING

GAS SECTION

Next: End

NOT OPENING ELECTRICALLY SOUND

GAS SECTION

Next: End

RESTRICTED FAN PRESSURE

FLUE ASSEMBLY

Next: End

SPARKING NOT LIGHTING WRONG MIX

GAS SECTION

Next: End

FUSE INVESTIGATION

PCB - FUSE

Next: End

NO SPARKING

CONDENSATE PUMP

Next: End

HALL SENSOR SIGNALZ

FAN

Next: End

NOT SPARKINGZ

PCB

Next: End

HALL SENSOR SIGNAL

FAN

Next: End

NOT SPARKING

PCB

Next: End

BOILER AND SYS COOL

PARTIAL LOAD SETTING

Next: End

FAULT CODE F75 3

SENSOR - WATER PRESSURE

Next: End

FAULT CODE F75 2

SENSOR - WATER PRESSURE

Next: End

NOT RUNNING

PUMP

Next: End

FAULT CODE F75 4

SENSOR - WATER PRESSURE

Next: End

FAULT CODE F75

SENSOR - WATER PRESSURE

Next: End

FAULT CODE F77

PCB

Next: End

FAULT CODE F77 2

PCB

Next: End

DHW DEMAND

CONDENSATE PUMP

Next: End

NOT SENSING DEMAND3

SENSOR - FLOW

Next: End

NOT RECOGNISING DEMAND3

PCB

Next: End

NOT SENSING DEMAND

SENSOR - FLOW

Next: End

NOT RECOGNISING DEMAND

PCB

Next: End

STEPPER MOTOR HAS DAMAGED PCB DBREF 13677

GAS VALVE AND PCB

Next: End

BOTTOM SOLENOID HAS DAMAGED PCB DBREF 13677

GAS VALVE AND PCB

Next: End

TOP SOLENOID DAMAGED PCB DBREF 13677

GAS VALVE AND PCB

Next: End

LOW WATER PRESSURE SWITCH

SENSOR - WATER PRESSURE

Next: End

DISPLAY PCB

DISPLAY - PLUS

Next: End

HARNESS DISPLAY PCB

CABLE - DISPLAY

Next: End

FURTHER INVESTIGATION FUSE F1

Z DIRECTION CHOICE OR CONTINUE

Next: End

VENTURI AIR MASS SENSOR

VENTURI AIR MASS SENSOR

Next: End

NOT RESPONDING TO VARYING AIRFLOW DB REF 15027

VENTURI AIR MASS SENSOR

Next: End

NO VOLTAGE AT REST DB REF 15027

VENTURI AIR MASS SENSOR

Next: End

BAFFLING DB REF 15027

GAS SECTION

Next: End

NOT RESPONDING TO VARYING AIRFLOW DB REF 15027 (2)

VENTURI AIR MASS SENSOR

Next: End

NO VOLTAGE AT REST DB REF 15027 (2)

VENTURI AIR MASS SENSOR

Next: End

BAFFLING DB REF 15027 (2)

GAS SECTION

Next: End

FLOW THERMISTOR SATISFACTORY

RESULT AS EXPECTED

Next: End

RETURN THERMISTOR SATISFACTORY

RESULT AS EXPECTED

Next: End

DHW SENSOR

RESULT AS EXPECTED

Next: End

WARMSTART SENSOR

RESULT AS EXPECTED

Next: End

PCB GAS VALVE VOLTAGE BOTTOM SOLENOID

RESULT AS EXPECTED

Next: End

GAS VALVE TOP SOLENOID

RESULT AS EXPECTED

Next: End

GAS VALVE BOTTOM SOLENOID

RESULT AS EXPECTED

Next: End

PCB GAS VALVE VOLTAGE TOP SOLENOID

RESULT AS EXPECTED

Next: End

GAS VALVE STEPPER MOTOR

RESULT AS EXPECTED

Next: End

PUMP

RESULT AS EXPECTED

Next: End

DIVERTER VALVE MOTOR

RESULT AS EXPECTED

Next: End

PCB VOLTAGE TO DIVERTER VALVE

RESULT AS EXPECTED

Next: End

DHW FLOW TURBINE

RESULT AS EXPECTED

Next: End

NOT CONTROLLING HW TEMP

PCB

Next: End

DHW SENSOR

HARNESS - WIRING (X2)

Next: End

PASSING TO RADS

VALVE - DIVERTER - BRASS

Next: End

TOO LOW FOR PERFORMANCE TEST

GAS INLET PRESSURE

Next: End

PERFORMANCE ANALYSIS FAIL

VENTURI AIR MASS SENSOR

Next: End

PERFORMANCE TEST FAIL

COMBUSTION ADJUSTMENT

Next: End

DHW TOO COOL

HARNESS - WIRING (X2)

Next: End

DHW TOO COOL

PCB

Next: End

SCALED-NOISY

HEAT EXCHANGER PRIMARY

Next: End

NOISY CH

Next: End

BLOCKED

EXPANSION VESSEL PIPE

Next: End

WARM START SENSOR

HARNESS - WIRING (X2)

Next: End

F22 F73 F74 FAULT CODES

SENSOR - WATER PRESSURE

Next: End

THERMISTOR FAULT CODES RETURN SENSOR

HARNESS - WIRING (X20 AND X25)

Next: End

THERMISTOR FAULT CODES FLOW SENSOR

HARNESS - WIRING (X20 AND X25)

Next: End

THERMISTOR FAULT CODES

PCB

Next: End

F13

PCB

Next: End

F13

HARNESS - WIRING (X2)

Next: End

F23 F24 F83 F84

HEAT EXCHANGER PRIMARY

Next: End

NOT RESPONDING TO VARYING AIRFLOW F52, F53

VENTURI AIR MASS SENSOR

Next: End

NO VOLTAGE AT REST F52, F53

VENTURI AIR MASS SENSOR

Next: End

F52 F53 FAULT CODE

PCB

Next: End

STEPPER MOTOR F26

GAS SECTION

Next: End

F26

PCB

Next: End

F25 F76

PCB

Next: End

F25 F76

HARNESS - WIRING (X20 AND X25)

Next: End

F25 F76

SAFETY FUSE

Next: End

F27 F62

PCB

Next: End

F20

PCB

Next: End

F20

HARNESS - WIRING (X20 AND X25)

Next: End

F20 2

HARNESS - WIRING (X20 AND X25)

Next: End

F49

Next: End

TOO LOW FOR PERFORMANCE TEST F93

GAS INLET PRESSURE

Next: End

PERFORMANCE ANALYSIS FAIL F93

VENTURI AIR MASS SENSOR

Next: End

PERFORMANCE TEST FAIL F93

COMBUSTION ADJUSTMENT

Next: End

F61

PCB

Next: End

F61

GAS SECTION

Next: End

F61 (2)

GAS SECTION

Next: End

F61 (3)

GAS SECTION

Next: End

TO CODING RESISTOR

HARNESS - WIRING (X20 AND X25)

Next: End

LIMITER BLOCKED

CHARACTERISTIC TEST FROM INSPECTION FLOW LIMITER AND FILTER

Next: !p114

FILTER BLOCKED

CHARACTERISTIC TEST FROM INSPECTION FLOW LIMITER AND FILTER

Next: !p116

NO VOLTAGE PRESENT

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: p1198

VOLTAGE PRESENT BUT DOES NOT INCREASE WHEN FAN RUNS

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: !p1200

PRESSURE DOES NOT REACH -1.5MB OR IS POSITIVE

CHARACTERISTIC TEST FROM PRESSURE FAN

Next: p1311

PRESSURE -1.5MB OR GREATER BUT DOES NOT EQUALISE TO 0MB DURING SPARKING

CHARACTERISTIC TEST FROM PRESSURE FAN

Next: p1313

VOLTAGE INCORRECT OR MISSING FROM PIN 3 (2 REDS)

CHARACTERISTIC TEST FROM VOLTAGE TO STEPPER MOTOR

Next: !p1316

VOLTAGE PRESENT ON PIN 3 BUT OTHER VOLTAGES INCORRECT OR MISSING

CHARACTERISTIC TEST FROM VOLTAGE TO STEPPER MOTOR

Next: p1318

PUMP DOES NOT RUN

CHARACTERISTIC TEST FROM OBSERVATION PUMP RUNS STANDBY

Next: p1449

PUMP RUNS OR F75 OCCURING INTERMITTENTLY

CHARACTERISTIC TEST FROM OBSERVATION PUMP RUNS STANDBY

Next: p1451

INLET PRESSURE SATISFACTORY BUT BURNER DROPS OUT ON MINIMUM

CHARACTERISTIC TEST FROM FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

Next: p1639

NO VOLTAGE PRESENT

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: p1647

VOLTAGE PRESENT BUT DOES NOT INCREASE WHEN FAN RUNS

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: !p1649

INLET PRESSURE SATISFACTORY BUT BURNER DROPS OUT ON MINIMUM

CHARACTERISTIC TEST FROM FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

Next: p1661

NO VOLTAGE PRESENT

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: p1669

VOLTAGE PRESENT BUT DOES NOT INCREASE WHEN FAN RUNS

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: !p1671

SPARKING DOES NOT OCCUR

CHARACTERISTIC TEST FROM OBSERVATION BURNER IGNITION AND ESTABLISH

Next: p1418

SPARKING OCCURS BUT BURNER DOES NOT IGNITE

CHARACTERISTIC TEST FROM OBSERVATION BURNER IGNITION AND ESTABLISH

Next: p184

BURNER IGNITES BUT DOES NOT ESTABLISH - RECTIFICATION ISSUE

CHARACTERISTIC TEST FROM OBSERVATION BURNER IGNITION AND ESTABLISH

Next: p1237

BURNER IGNITES BUT BAFFLES OUT/NOISY - COMBUSTION ISSUE

CHARACTERISTIC TEST FROM OBSERVATION BURNER IGNITION AND ESTABLISH

Next: p1106

DHW TOO HOT

CHARACTERISTIC TEST FROM OPERATION DHW

Next: p279

DHW TOO COOL RADS REMAIN COOL WITH NO CH DEMAND

CHARACTERISTIC TEST FROM OPERATION DHW

Next: p398

DHW TOO COOL RADIATORS BEGIN TO HEAT WITH NO CH DEMAND

CHARACTERISTIC TEST FROM OPERATION DHW

Next: p283

BOILER NOISY KETTLING

CHARACTERISTIC TEST FROM OPERATION DHW

Next: p1163

BOILER DOES NOT RESPOND TO CENTRAL HEATING

CHARACTERISTIC TEST FROM CH OPERATION (NOISY?)

Next: p312

BOILER STILL NOISY

CHARACTERISTIC TEST FROM CH OPERATION (NOISY?)

Next: !p1096

INLET PRESSURE UNSATISFACTORY

CHARACTERISTIC TEST FROM FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

Next: !p371

INLET PRESSURE SATISFACTORY BUT FGA READINGS OUTSIDE MANUFACTURERS LIMITS

CHARACTERISTIC TEST FROM FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

Next: p373

NO VOLTAGE PRESENT

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: p379

VOLTAGE PRESENT BUT DOES NOT INCREASE WHEN FAN RUNS

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: !p378

DIFFERENTIAL EXCESSIVE

CHARACTERISTIC TEST FROM DIFFERENTIAL PRIMARY HEAT EXCHANGER

Next: !p1099

BOILER DOES NOT RESPOND TO CENTRAL HEATING

CHARACTERISTIC TEST FROM CH OPERATION (NOISY?)

Next: p413

BOILER NOISY

CHARACTERISTIC TEST FROM OPERATION CH

Next: p439

BOILER UP TO TEMP RADS COLD

CHARACTERISTIC TEST FROM OPERATION CH

Next: p470

BOILER AND SYSTEM TEMPERATURE LOW

CHARACTERISTIC TEST FROM OPERATION CH

Next: p1439

DIFFERENTIAL INCORRECT OR LOCAL NOISE

CHARACTERISTIC TEST FROM DIFFERENTIAL PRIMARY HEAT EXCHANGER FOR CH NOISE

Next: !p465

DIFFERENTIAL OK SYSTEM NOISE

CHARACTERISTIC TEST FROM DIFFERENTIAL PRIMARY HEAT EXCHANGER FOR CH NOISE

Next: !p467

BOILER DOES NOT GIVE THE OPTION OF ACTIVATING WARMSTART

CHARACTERISTIC TEST FROM OBSERVATION PREHEAT OPERATION

Next: p504

BOILER DOES NOT HEAT SUFFICIENTLY ON WARM START

CHARACTERISTIC TEST FROM OBSERVATION PREHEAT OPERATION

Next: p506

BOILER FIRES WITH NO DEMAND

CHARACTERISTIC TEST FROM OBSERVATION SELF CHECK

Next: p660

FAULT CODE SHOWN

CHARACTERISTIC TEST FROM OBSERVATION SELF CHECK

Next: p670

DIFFERENTIAL EXCESSIVE

CHARACTERISTIC TEST FROM DIFFERENTIAL PRIMARY HEAT EXCHANGER

Next: p779

BOILER DOES NOT RESPOND TO CENTRAL HEATING

CHARACTERISTIC TEST FROM CH OPERATION (NOISY?)

Next: p746

NO VOLTAGE PRESENT

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: p806

VOLTAGE PRESENT BUT DOES NOT INCREASE WHEN FAN RUNS

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: !p808

VOLTAGE INCORRECT OR MISSING FROM PIN 3 (2 REDS)

CHARACTERISTIC TEST FROM VOLTAGE TO STEPPER MOTOR

Next: !p823

VOLTAGE PRESENT ON PIN 3 BUT OTHER VOLTAGES INCORRECT OR MISSING

CHARACTERISTIC TEST FROM VOLTAGE TO STEPPER MOTOR

Next: p825

INLET PRESSURE UNSATISFACTORY

CHARACTERISTIC TEST FROM FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

Next: !p944

INLET PRESSURE SATISFACTORY BUT FGA READINGS OUTSIDE MANUFACTURERS LIMITS

CHARACTERISTIC TEST FROM FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

Next: p946

NO VOLTAGE PRESENT

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: p949

VOLTAGE PRESENT BUT DOES NOT INCREASE WHEN FAN RUNS

CHARACTERISTIC TEST FROM VOLTAGES AIR MASS SENSOR OPERATION

Next: !p951

VOLTAGE TO DISPLAY PCB AT MAIN PCB

REMOVE THE DISPLAY HARNESS CONNECTOR FROM THE MAIN PCB

Next: p1023, !f1024

INSPECTION DHW ISOLATION VALVE

Next: p111, !f117

RESISTANCE DHW SENSOR

REMOVE THE CONNECTOR FROM THE DHW SENSOR

Next: !p1140, !f1141

VOLTAGE DIVERTER VALVE

REMOVE THE CONNECTOR FROM THE DIVERTER VALVE MOTOR AND MAKE SAFE
NO DEMANDS

Next: p1153, !f1151

VOLTAGE DIVERTER VALVE

REMOVE THE CONNECTOR FROM THE DIVERTER VALVE MOTOR AND MAKE SAFE
NO DEMANDS

Next: p1157, !f1158

VOLTAGE MAINS POWER INPUT TO APPLIANCE

{GAINPCBACS}

Next: p1577, f1282

RESISTANCE MAINS SUPPLY FUSE

REMOVE THE MAINS 3A FUSE FROM ITS FOLDER

Next: !p1283, f1284

FUSE FURTHER INVESTIGATION MAINS

Next: !p1285, !f1286

RESISTANCE GAS VALVE TOP SOLENOID AND HARNESS

REMOVE CONNECTOR X25 FROM THE PCB

Next: !p1323, f1324

RESISTANCE GAS VALVE HARNESS TOP SOLENOID

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE TOP SOLENOID (BLACK)

Next: !p1325, !f1326

RESISTANCE GAS VALVE HARNESS BOTTOM SOLENOID

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE BOTTOM SOLENOID (WHITE)

Next: !p1331, !f1332

VOLTAGE DC SUPPLY TO FAN AT PCB

{GAINPCBACS}
REMOVE 4 WIRE CONNECTOR FROM FAN AND MAKE SAFE

Next: p1359, f1373

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p1362, !f1363

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p1374, !f1375

RESISTANCE FAN HARNESS DC

REMOVE CONNECTOR X20 FROM THE PCB
REMOVE THE DC FAN CONNECTOR (4WIRE) FROM THE FAN ASSEMBLY

Next: p1381, !f1382

VOLTAGE DC SUPPLY TO FAN AT PCB

{GAINPCBACS}
REMOVE 4 WIRE CONNECTOR FROM FAN AND MAKE SAFE

Next: p1396, !f1399

RESISTANCE PUMP AND HARNESS_FUSE

REMOVE CONNECTOR X18 FROM THE PCB

Next: !p1401, !f1402

DISCONNECT X40 DOES SPARKING OCCUR?

REMOVE CONNECTOR X40 FROM THE PCB AND MAKE SAFE

Next: !p1421, f1422

VOLTAGE HALL SENSOR

{GAINPCBACS}

Next: p1423, f1424

RESISTANCE FAN HARNESS DC

REMOVE CONNECTOR X20 FROM THE PCB
REMOVE THE DC FAN CONNECTOR (4WIRE) FROM THE FAN ASSEMBLY

Next: !p1425, !f1426

RESISTANCE FAN HARNESS DC

REMOVE CONNECTOR X20 FROM THE PCB
REMOVE THE DC FAN CONNECTOR (4WIRE) FROM THE FAN ASSEMBLY

Next: !p1433, !f1434

OBSERVATION PUMP RUNS STANDBY

Next: p1447, ?1448, ?1450

RESISTANCE LOW WATER PRESSURE SWITCH HARNESS

REMOVE CONNECTOR X2 FROM THE PCB
REMOVE CONNECTOR FROM THE LOW WATER PRESSURE SWITCH

Next: !p1458, !f1459

RESISTANCE LOW WATER PRESSURE SWITCH HARNESS

REMOVE CONNECTOR X2 FROM THE PCB
REMOVE CONNECTOR FROM THE LOW WATER PRESSURE SWITCH

Next: !p1478, !f1479

OBSERVATION CONNECTOR X40 (CONDENSATE PUMP)

GAIN ACCESS TO PCB

Next: !p1490, f1491

OBSERVATION F77 RESET (CONDENSATE PUMP DISCONNECTED)

REMOVE CONDENSATE PUMP CONNECTOR FROM X40 AND MAKE SAFE

Next: !p1492, !f1493

OBSERVATION CONNECTOR X100 (CONDENSATE PUMP)

GAIN ACCESS TO PCB

Next: p1495, f1496

DISCONNECT X100 CONDENSATE PUMP - DHW DEMAND RECOGNISED?

REMOVE CONNECTOR X100 (BLUE) FROM THE PCB AND MAKE SAFE, CONNECT A WIRE LINK BETWEEN THE CONNECTIONS

Next: !p1497, f1498

VOLTAGE DEMAND FROM AQUA SENSOR

{GAINPCBACS}
HOT WATER TAP ON WITH A FLOW RATE OF 3 L/MIN

Next: p1499, f1500

VOLTAGE TO AQUA SENSOR

Next: p1501, !f1502

VOLTAGE TO AQUA SENSOR

Next: p1513, !f1514

VOLTAGE 22V AND 5V LINES X2 DISCONNECTED

REMOVE CONNECTOR X2 (BLUE) FROM THE PCB

Next: p1549, f1550

VOLTAGE 22V AND 5V LINES X25 DISCONNECTED

REMOVE CONNECTOR X25 (WHITE) FROM THE PCB

Next: p1551, !f1552

RESISTANCE STEPPER MOTOR HARNESS

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE STEPPER MOTOR

Next: !p1555, !f1556

RESISTANCE GAS VALVE HARNESS BOTTOM SOLENOID

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE BOTTOM SOLENOID (WHITE)

Next: !p1559, !f1560

RESISTANCE GAS VALVE HARNESS TOP SOLENOID

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE TOP SOLENOID (BLACK)

Next: !p1563, !f1564

VOLTAGE TO DISPLAY PCB AT MAIN PCB

REMOVE THE DISPLAY HARNESS CONNECTOR FROM THE MAIN PCB

Next: !p1571, !f1572

FUSE FURTHER INVESTIGATION F1

Next: !p1610, !f1611

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: !p1690, !f1691

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: !p1694, !f1695

RESISTANCE DHW SENSOR

REMOVE THE CONNECTOR FROM THE DHW SENSOR

Next: !p1698, !f1699

RESISTANCE WARM START SENSOR

REMOVE THE CONNECTOR FROM THE WARM START SENSOR

Next: !p1702, !f1703

VOLTAGE SOLENOID BOTTOM

Next: !p1706, !f1707

RESISTANCE GAS VALVE TOP SOLENOID AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: !p1710, !f1711

RESISTANCE GAS VALVE BOTTOM SOLENOID AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: !p1714, !f1715

VOLTAGE SOLENOID TOP

NO DEMANDS

Next: !p1718, !f1719

RESISTANCE GAS VALVE STEPPER MOTOR AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: !p1722, !f1723

RESISTANCE PUMP AND HARNESS_FUSE

REMOVE CONNECTOR X18 FROM THE PCB

Next: !p1726, !f1727

RESISTANCE DIVERTER VALVE MOTOR AND HARNESS

REMOVE CONNECTOR X2 FROM THE PCB

Next: !p1730, !f1731

VOLTAGE DIVERTER VALVE

REMOVE THE CONNECTOR FROM THE DIVERTER VALVE MOTOR AND MAKE SAFE
NO DEMANDS

Next: !p1734, !f1735

VOLTAGE DEMAND FROM AQUA SENSOR

{GAINPCBACS}
HOT WATER TAP ON WITH A FLOW RATE OF 3 L/MIN

Next: !p1738, !f1739

RESISTANCE DHW SENSOR

REMOVE THE CONNECTOR FROM THE DHW SENSOR

Next: !p297, !f298

VOLTAGE FROM 24V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p319, f452

RESISTANCE DHW SENSOR

REMOVE THE CONNECTOR FROM THE DHW SENSOR

Next: !p401, !f402

DIFFERENTIAL PRIMARY HEAT EXCHANGER

ATTACH TEMPERATURE CLAMPS AS INDICATED BY RED ARROWS
BOILER CH THERMOSTAT SET TO MAX

Next: p1100, ?410, ?412

VOLTAGE FROM 24V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p416, f454

INSPECTION AIR INTAKE TUBE

REMOVE AIR INTAKE TUBE

Next: p1214, !f436

240V OR 24V CONTROLS?

{GAINPCBACS}

Next: p446, f447

VOLTAGE FROM 24V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p448, f453

PRESSURE EXPANSION VESSEL

APPLIANCE PRIMARY CIRCUIT DRAINED AND DISCHARGED

Next: !p497, !f498

RESISTANCE WARM START SENSOR

REMOVE THE CONNECTOR FROM THE WARM START SENSOR

Next: !p509, !f510

OBSERVATION SYSTEM PRESSURE

Next: p700, !f699

VOLTAGE TO LOW PRESSURE SWITCH

Next: p703, !f704

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: !p717, !f715

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: !p716, !f714

OBSERVATION SYSTEM PRESSURE

Next: p732, !f755

DIFFERENTIAL PRIMARY HEAT EXCHANGER

ATTACH TEMPERATURE CLAMPS AS INDICATED BY RED ARROWS
BOILER CH THERMOSTAT SET TO MAX

Next: p1103, ?743, ?745

VOLTAGE FROM 24V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p749, f750

RESISTANCE WARM START SENSOR AND HARNESS

REMOVE CONNECTOR X2 FROM THE PCB

Next: !p763, f764

RESISTANCE WARM START SENSOR

REMOVE THE CONNECTOR FROM THE WARM START SENSOR

Next: !p765, !f766

PCBS REPLACED?

Next: p793, !f800

RESISTANCE CODING RESISTOR

DISCONNECT THE INLINE CONNECTOR TO THE SAFETY FUSE AND CODING RESISTOR

Next: !p986, !f987

VOLTAGE TO STEPPER MOTOR

NO DEMANDS

Next: !p840, ?822, ?824

RESISTANCE SAFETY FUSE AND HARNESS

REMOVE CONNECTOR X20 FROM THE PCB

Next: !p843, f844

RESISTANCE SAFETY FUSE AND SAFETY FUSE HARNESS

DISCONNECT THE INLINE CONNECTOR TO THE SAFETY FUSE HARNESS FROM THE MAIN BOILER HARNESS

Next: !p845, f846

RESISTANCE SAFETY FUSE HARNESS

DISCONNECT THE INLIN

Next: !p847, !f848

TIGHTNESS TEST INSTALLATION

Next: p852, !f851

RESISTANCE FLOW SENSOR AND HARNESS

REMOVE CONNECTOR X20 FROM THE PCB

Next: p925, f926

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: !p935, !f936

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: !p933, !f934

OBSERVATION REMOVE EBUS CONNECTOR

REMOVE THE EBUS CONNECTOR FROM THE PCB AND MAKE SAFE

Next: !p939, !f940

FGA MAXIMUM, MINIMUM AND PRESSURE GAS INLET

ATTACH A U GAUGE TO

Next: !p966, ?943, ?945, ?1660

INSPECTION AIR INTAKE TUBE

REMOVE AIR INTAKE TUBE

Next: p1223, !f959

RESISTANCE GAS VALVE BOTTOM SOLENOID AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: p974, f976

RESISTANCE GAS VALVE HARNESS BOTTOM SOLENOID

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE BOTTOM SOLENOID (WHITE)

Next: !p981, !f982

RESISTANCE GAS VALVE HARNESS TOP SOLENOID

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE TOP SOLENOID (BLACK)

Next: !p983, !f988

RESISTANCE STEPPER MOTOR HARNESS

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE STEPPER MOTOR

Next: !p984, !f985

RESISTANCE HARNESS DISPLAY PCB

REMOVE DISPLAY HARNESS FROM X51 CONNECTIONS

Next: !p1025, !f1026

FAULT CODES 2

Next: !p1028, !f1029

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p1034, !f1035

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p1036, !f1037

OBSERVATION DHW DEMAND INCORRECTLY RECOGNISED

HOT WATER TAPS OFF

Next: p1038, !f1039

OBSERVATION ISOLATE MAINS WATER - DEMAND STOPS?

ENSURE LEFT HAND FILLING TAP CLOSED
TURN RIGHT HAND FILLING TAP TO THE OPEN POSITION

Next: !p1040, !f1041

INSPECTION AIR INTAKE TUBE

REMOVE AIR INTAKE TUBE

Next: p188, !f1070

RESISTANCE CODING RESISTOR GAS GROUP

REMOVE THE CODING RESISTOR FROM THE PCB

Next: !p1236, !f1075

RESISTANCE HARNESS AIR MASS SENSOR

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE CONNECTOR FROM THE MASS FLOW SENSOR

Next: !p1078, !f1079

RESISTANCE HARNESS AIR MASS SENSOR

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE CONNECTOR FROM THE MASS FLOW SENSOR

Next: !p1083, !f1084

INSPECTION FILTER PRIMARY CIRCUIT

APPLIANCE DRAINED AND DISCHARGED

Next: !p1101, !f1102

INSPECTION FILTER PRIMARY CIRCUIT

APPLIANCE DRAINED AND DISCHARGED

Next: !p1104, !f1105

PRESSURE GAS INLET

ATTACH PRESSURE GAUGE TO THE INLET PRESSURE TEST POINT

Next: p1050, !f1128

INSPECTION FLOW LIMITER AND FILTER

DHW SUPPLY ISOLATED

Next: !p112, ?113, ?115

RESISTANCE DHW SENSOR AND HARNESS

REMOVE CONNECTOR X2 FROM THE PCB

Next: p1033, f1139

RESISTANCE DIVERTER VALVE HARNESS

REMOVE CONNECTOR X2 FROM THE PCB
REMOVE THE CONNECTOR FROM THE DIVERTER VALVE MOTOR

Next: !p1154, !f1155

RESISTANCE DIVERTER VALVE HARNESS

REMOVE CONNECTOR X2 FROM THE PCB
REMOVE THE CONNECTOR FROM THE DIVERTER VALVE MOTOR

Next: !p1159, !f1160

LIMPET CHECK

Next: p285, !f1178

LIMPET CHECK

Next: p461, !f1189

LIMPET CHECK

Next: p535, !f1194

VOLTAGES AIR MASS SENSOR OPERATION

{GAINPCBACS}
NO DEMANDS

Next: p1196, ?1197, ?1199

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: p1205, !f1206

VOLTAGE TO AIR MASS SENSOR

Next: p1201, !f1202

RESISTANCE HARNESS AIR MASS SENSOR

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE CONNECTOR FROM THE MASS FLOW SENSOR

Next: !p1203, !f1204

INSPECTION PRIMARY HEAT EXCHANGER FLUEWAYS

REMOVE THE BURNER DOOR AND FAN ASSEMBLY

Next: p1211, !f1209

INSPECTION FLUE

Next: !p1213, !f1212

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: p1215, !f1216

INSPECTION PRIMARY HEAT EXCHANGER FLUEWAYS

REMOVE THE BURNER DOOR AND FAN ASSEMBLY

Next: p1220, !f1218

INSPECTION FLUE

Next: !p1222, !f1221

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: p1224, !f1225

INSPECTION PRIMARY HEAT EXCHANGER FLUEWAYS

REMOVE THE BURNER DOOR AND FAN ASSEMBLY

Next: p1229, !f1227

INSPECTION FLUE

Next: !p1231, !f1230

INSPECTION FILTER PRIMARY CIRCUIT

APPLIANCE DRAINED AND DISCHARGED

Next: !p1233, !f1234

INSPECTION AIR INTAKE TUBE

REMOVE AIR INTAKE TUBE

Next: p1238, !f1247

PRESSURE GAS INLET

ATTACH PRESSURE GAUGE TO THE INLET PRESSURE TEST POINT

Next: p1239, !f1240

RESISTANCE IGNITION LEAD

REMOVE THE IGNITION LEAD FROM THE PCB
REMOVE THE IGNITION LEAD FROM THE SPARK ELECTRODE

Next: p1241, !f1242

INSPECTION SPARK ELECTRODE

REMOVE THE SPARK ELECTRODE ASSEMBLY

Next: p1243, !f1244

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: !p1245, !f1246

INSPECTION AIR INTAKE TUBE

REMOVE AIR INTAKE TUBE

Next: p1304, !f1305

INSPECTION AIR MASS SENSOR

REMOVE AIR INTAKE TUBE

Next: p1306, !f1307

PRESSURE FAN

ATTACH PRESSURE TUBE

Next: p1308, ?1310, ?1312

INSPECTION SPARK ELECTRODE

REMOVE THE SPARK ELECTRODE ASSEMBLY

Next: p1341, !f1342

INSPECTION CONDENSATE TRAP

Next: p1335, !f1336

VOLTAGE TO STEPPER MOTOR

NO DEMANDS

Next: p1314, ?1315, ?1317

VOLTAGE SOLENOID TOP

NO DEMANDS

Next: p1321, f1322

RESISTANCE STEPPER MOTOR HARNESS

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE STEPPER MOTOR

Next: !p1319, !f1320

VOLTAGE SOLENOID BOTTOM

Next: p1327, !f1328

RESISTANCE GAS VALVE BOTTOM SOLENOID AND HARNESS

REMOVE CONNECTOR X25 FROM THE PCB

Next: p1329, f1330

RESISTANCE CODING RESISTOR GAS GROUP

REMOVE THE CODING RESISTOR FROM THE PCB

Next: !p1333, !f1334

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: p1337, !f1338

INSPECTION PRIMARY HEAT EXCHANGER FLUEWAYS

REMOVE THE BURNER DOOR AND FAN ASSEMBLY

Next: !p1339, !f1340

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: !p1343, !f1344

VOLTAGE DC PWM DEMAND AT PCB

{GAINPCBACS}
REMOVE 4 WIRE FAN CONNECTOR FROM FAN AND MAKE SAFE

Next: p1370, f1361

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p1364, !f1365

RESISTANCE DHW SENSOR

REMOVE THE CONNECTOR FROM THE DHW SENSOR

Next: !p1366, !f1367

RESISTANCE FAN HARNESS DC

REMOVE CONNECTOR X20 FROM THE PCB
REMOVE THE DC FAN CONNECTOR (4WIRE) FROM THE FAN ASSEMBLY

Next: !p1371, !f1372

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p1376, !f1377

RESISTANCE DHW SENSOR

REMOVE THE CONNECTOR FROM THE DHW SENSOR

Next: !p1378, !f1379

OBSERVATION FAN RUNS

Next: p1383, f1395

VOLTAGE HALL SENSOR

{GAINPCBACS}

Next: !p1393, !f1394

VOLTAGE DC PWM DEMAND AT PCB

{GAINPCBACS}
REMOVE 4 WIRE FAN CONNECTOR FROM FAN AND MAKE SAFE

Next: !p1397, !f1398

OBSERVATION CONNECTOR X40 (CONDENSATE PUMP)

GAIN ACCESS TO PCB

Next: p1419, f1420

VOLTAGE HALL SENSOR

{GAINPCBACS}

Next: p1431, f1432

RESISTANCE IGNITION LEAD

REMOVE THE IGNITION LEAD FROM THE PCB
REMOVE THE IGNITION LEAD FROM THE SPARK ELECTRODE

Next: p1427, !f1428

INSPECTION SPARK ELECTRODE

REMOVE THE SPARK ELECTRODE ASSEMBLY

Next: !p1429, !f1430

RESISTANCE IGNITION LEAD

REMOVE THE IGNITION LEAD FROM THE PCB
REMOVE THE IGNITION LEAD FROM THE SPARK ELECTRODE

Next: p1435, !f1436

INSPECTION SPARK ELECTRODE

REMOVE THE SPARK ELECTRODE ASSEMBLY

Next: !p1437, !f1438

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p1440, !f1441

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p1442, !f1443

OBSERVATION HEATING PARTIAL LOAD SETTING (PARAMETER D 000)

ENSURE NO DEMANDS

Next: !p1444, !f1445

OBSERVATION SYSTEM PRESSURE

Next: p1472, !f1473

VOLTAGE PUMP AT PCB 1

{GAINPCBACS}

Next: p1468, !f1469

OBSERVATION SYSTEM PRESSURE

Next: p1452, !f1453

VOLTAGE TO LOW PRESSURE SWITCH

Next: p1454, !f1455

LIMPET CHECK

Next: p1460, !f1461

PRESSURE EXPANSION VESSEL

APPLIANCE PRIMARY CIRCUIT DRAINED AND DISCHARGED

Next: p1464, !f1465

INSPECTION FILTER PRIMARY CIRCUIT

APPLIANCE DRAINED AND DISCHARGED

Next: !p1466, !f1467

VOLTAGE PUMP AT PCB 2

REMOVE THE CONNECTOR

Next: !p1470, !f1471

VOLTAGE TO LOW PRESSURE SWITCH

Next: p1474, !f1475

CHECK PUMP OPERATION

REMOVE VENT PLUG FRO

Next: p1480, !f1481

PRESSURE EXPANSION VESSEL

APPLIANCE PRIMARY CIRCUIT DRAINED AND DISCHARGED

Next: p1484, !f1485

INSPECTION FILTER PRIMARY CIRCUIT

APPLIANCE DRAINED AND DISCHARGED

Next: !p1486, !f1487

VOLTAGE DEMAND FROM AQUA SENSOR

{GAINPCBACS}
HOT WATER TAP ON WITH A FLOW RATE OF 3 L/MIN

Next: p1511, f1512

RESISTANCE CHECK AQUA SENSOR HARNESS

REMOVE THE CONNECTOR FROM THE AQUA SENSOR
REMOVE CONNECTOR X2 FROM THE PCB

Next: !p1503, !f1504

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p1507, !f1508

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: !p1509, !f1510

RESISTANCE CHECK AQUA SENSOR HARNESS

REMOVE THE CONNECTOR FROM THE AQUA SENSOR
REMOVE CONNECTOR X2 FROM THE PCB

Next: !p1515, !f1516

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p1519, !f1520

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p1521, !f1522

INSPECTION BURNER OFF LINK

Next: !p1523, !f1524

VOLTAGE 22V AND 5V LINES

Next: p1547, f1548

VOLTAGE 22V AND 5V LINES LOW WATER PRESSURE SWITCH DISCONNECTED

REMOVE THE CONNECTOR

Next: !p1567, !f1568

RESISTANCE GAS VALVE STEPPER MOTOR AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: p1553, f1554

RESISTANCE GAS VALVE BOTTOM SOLENOID AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: p1557, f1558

RESISTANCE GAS VALVE TOP SOLENOID AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: p1613, f1562

RESISTANCE FUSE F1

REMOVE FUSE F1 FROM ITS HOLDER ON THE PCB

Next: p1546, f1609

VOLTAGE 22V AND 5V LINES AIR MASS SENSOR DISCONNECTED

REMOVE CONNECTOR FRO

Next: !p1614, !f1615

INSPECTION AIR INTAKE TUBE

REMOVE AIR INTAKE TUBE

Next: p1640, !f1641

INSPECTION CONDENSATE TRAP

Next: p1642, !f1643

VOLTAGES AIR MASS SENSOR OPERATION

{GAINPCBACS}
NO DEMANDS

Next: p1644, ?1646, ?1648

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: p1654, !f1655

VOLTAGE TO AIR MASS SENSOR

Next: p1650, !f1651

RESISTANCE HARNESS AIR MASS SENSOR

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE CONNECTOR FROM THE MASS FLOW SENSOR

Next: !p1652, !f1653

INSPECTION PRIMARY HEAT EXCHANGER FLUEWAYS

REMOVE THE BURNER DOOR AND FAN ASSEMBLY

Next: p1656, !f1657

INSPECTION FLUE

Next: !p1658, !f1659

INSPECTION AIR INTAKE TUBE

REMOVE AIR INTAKE TUBE

Next: p1662, !f1663

INSPECTION CONDENSATE TRAP

Next: p1664, !f1665

VOLTAGES AIR MASS SENSOR OPERATION

{GAINPCBACS}
NO DEMANDS

Next: p1666, ?1668, ?1670

INSPECTION BURNER

REMOVE THE COMBUSTION FRONT ASSEMBLY

Next: p1676, !f1677

VOLTAGE TO AIR MASS SENSOR

Next: p1672, !f1673

RESISTANCE HARNESS AIR MASS SENSOR

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE CONNECTOR FROM THE MASS FLOW SENSOR

Next: !p1674, !f1675

INSPECTION PRIMARY HEAT EXCHANGER FLUEWAYS

REMOVE THE BURNER DOOR AND FAN ASSEMBLY

Next: p1678, !f1679

INSPECTION FLUE

Next: !p1680, !f1681

PRESSURE GAS INLET

ATTACH PRESSURE GAUGE TO THE INLET PRESSURE TEST POINT

Next: p1303, !f197

INSPECTION CONDENSATE TRAP

Next: p1195, !f254

RESISTANCE DHW SENSOR AND HARNESS

REMOVE CONNECTOR X2 FROM THE PCB

Next: p291, f294

INSPECTION DIVERTER VALVE MOTOR OPERATION

REMOVE THE DIVERTER

Next: !p356, f1149

CH OPERATION (NOISY?)

Next: p1232, ?311, ?313

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p292, !f295

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: !p293, !f296

240V OR 24V CONTROLS?

{GAINPCBACS}

Next: p315, f318

VOLTAGE FROM 240V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p316, !f317

VOLTAGES AIR MASS SENSOR OPERATION

{GAINPCBACS}
NO DEMANDS

Next: p374, ?375, ?377

VOLTAGE TO AIR MASS SENSOR

Next: p1077, !f1080

RESISTANCE DHW SENSOR AND HARNESS

REMOVE CONNECTOR X2 FROM THE PCB

Next: p399, f400

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p403, !f404

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p989, !f406

DIFFERENTIAL DHW HEAT EXCHANGER

ATTACH TEMPERATURE CLAMPS AS INDICATED BY THE RED ARROWS
BOILER DHW TEMPERATURE SET TO MAX

Next: !p407, f408

240V OR 24V CONTROLS?

{GAINPCBACS}

Next: p414, f415

VOLTAGE FROM 240V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p418, !f419

VOLTAGE FROM 240V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p450, !f451

INSPECTION INTEGRAL BYPASS

APPLIANCE DRAINED AND DISCHARGED

Next: p462, !f469

DIFFERENTIAL PRIMARY HEAT EXCHANGER FOR CH NOISE

ATTACH TEMPERATURE CLAMPS AS INDICATED BY THE RED ARROWS
BOILER CH THERMOSTAT SET TO MAX

Next: !p463, ?464, ?466

RESISTANCE WARM START SENSOR AND HARNESS

REMOVE CONNECTOR X2 FROM THE PCB

Next: !p507, f508

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p511, !f513

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p515, !f514

RESISTANCE WARM START SENSOR

REMOVE THE CONNECTOR FROM THE WARM START SENSOR

Next: !p516, !f517

INSPECTION DIVERTER VALVE MOTOR OPERATION

REMOVE THE DIVERTER

Next: p686, f1156

INSPECTION EXTERNAL BYPASS

Next: p1190, !f531

OBSERVATION CLOSE INTEGRAL BYPASS

CLOSE THE INTEGRAL B

Next: !p692, !f537

TEMPERATURE APPLIANCE FROST PROTECTION ?

ATTACH TEMPERATURE CLAMPS AS INDICATED BY THE RED ARROWS

Next: p1129, !f1042

FAULT CODES

Next: p1027, !f671

RESISTANCE LOW WATER PRESSURE SWITCH HARNESS

REMOVE CONNECTOR X2 FROM THE PCB
REMOVE CONNECTOR FROM THE LOW WATER PRESSURE SWITCH

Next: !p705, !f706

RESISTANCE FLOW SENSOR AND HARNESS

REMOVE CONNECTOR X20 FROM THE PCB

Next: p711, f712

RESISTANCE RETURN SENSOR AND HARNESS

REMOVE CONNECTOR X20 FROM THE PCB

Next: !p718, f713

RESISTANCE FLOW SENSOR

REMOVE THE CONNECTOR FROM THE FLOW SENSOR

Next: p734, !f757

RESISTANCE RETURN SENSOR

REMOVE THE CONNECTOR FROM THE RETURN SENSOR

Next: p735, !f758

LIMPET CHECK

Next: p739, !f759

DIFFERENTIAL DHW HEAT EXCHANGER

ATTACH TEMPERATURE CLAMPS AS INDICATED BY THE RED ARROWS
BOILER DHW TEMPERATURE SET TO MAX

Next: !p740, f741

240V OR 24V CONTROLS?

{GAINPCBACS}

Next: p747, f748

VOLTAGE FROM 240V EXTERNAL CONTROLS

{GAINPCBACS}
ENSURE ALL EXTERNAL CONTROLS ARE CALLING

Next: !p753, !f754

INSPECTION EXTERNAL BYPASS

Next: p1179, !f778

INSPECTION EXTERNAL BYPASS

Next: p780, !f782

INSPECTION INTEGRAL BYPASS

APPLIANCE DRAINED AND DISCHARGED

Next: !p781, !f783

RESISTANCE CODING RESISTOR OUTPUT AND HARNESS

REMOVE CONNECTOR X20 FROM THE PCB

Next: p1071, f795

VOLTAGES AIR MASS SENSOR OPERATION

{GAINPCBACS}
NO DEMANDS

Next: !p817, ?805, ?807

VOLTAGE TO AIR MASS SENSOR

Next: p809, !f810

RESISTANCE HARNESS AIR MASS SENSOR

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE CONNECTOR FROM THE MASS FLOW SENSOR

Next: !p811, !f812

RESISTANCE STEPPER MOTOR HARNESS

REMOVE CONNECTOR X25 FROM THE PCB
REMOVE THE CONNECTOR FROM THE STEPPER MOTOR

Next: !p826, !f827

INSPECTION SPARK ELECTRODE

REMOVE THE SPARK ELECTRODE ASSEMBLY

Next: !p854, !f853

RESISTANCE RETURN SENSOR AND HARNESS

REMOVE CONNECTOR X20 FROM THE PCB

Next: p928, f927

RESISTANCE IGNITION LEAD

REMOVE THE IGNITION LEAD FROM THE PCB
REMOVE THE IGNITION LEAD FROM THE SPARK ELECTRODE

Next: p929, !f931

INSPECTION SPARK ELECTRODE

REMOVE THE SPARK ELECTRODE ASSEMBLY

Next: !p930, !f932

VOLTAGES AIR MASS SENSOR OPERATION

{GAINPCBACS}
NO DEMANDS

Next: p947, ?948, ?950

VOLTAGE TO AIR MASS SENSOR

Next: p1082, !f1085

RESISTANCE GAS VALVE TOP SOLENOID AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: p975, f977

RESISTANCE GAS VALVE STEPPER MOTOR AND HARNESS AND TO EARTH

REMOVE CONNECTOR X25 FROM THE PCB

Next: !p979, f980

LIMPET CHECK

Next: p405, !f1006

System Information

  • Total Tests: 741
  • Sequence Logic: Decoded from encrypted .seq file
  • Navigation: Dynamic based on pass/fail results
  • Source: 4731307 GW SWIFTFLOW 100 SIT Control