Fault Code |
Fault Description |
Possible Causes |
Fault Code “com” |
Communication Error Between The Main PCB & The User Interface PCB |
- Loose Wiring Or Damaged Connection Between The Main PCB & The User Interface PCB
|
Fault Code F00 |
Heating Flow NTC Thermistor Fault |
- The Heating Flow NTC Thermistor Has Become Disconnected Or Has Gone Open Circuit (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Flow NTC Thermistor And The Main PCB
|
Fault Code F01 |
Heating Return NTC Thermistor Fault |
- The Heating Return NTC Thermistor Has Become Disconnected Or Has Gone Open Circuit (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Return NTC Thermistor And The Main PCB.
|
Fault Code F10 |
Heating Flow NTC Thermistor Fault |
- There Is A Short Circuit On The Heating Flow NTC Thermistor (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Flow NTC Thermistor And The Main PCB.
|
Fault Code F11 |
Heating Return NTC Thermistor Fault |
- There Is A Short Circuit On The Heating Return NTC Thermistor (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Return NTC Thermistor And The Main PCB
|
Fault Code F12 |
Domestic Hot Water Cylinder NTC Thermistor Fault (Not Applicable To This Appliance) |
|
Fault Code F13 |
Internal Domestic Hot Water Storage Tank NTC Thermistor Fault (Not Applicable To This Appliance) |
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Fault Code F17 |
Solar Return Thermistor Fault (Not Applicable To This Appliance) |
|
Fault Code F20 |
Overheat Fault (The Flow Or Return Pipe In The Appliance Has Reached 97 Degrees C) |
- Inadequate Pump Operation
- Blockage Or Air Lock Within The Appliance
- Check Domestic Hot Water Heat Exchanger and Domestic Hot Water Heat Exchanger Filter For Debris If Fault Occurs On Hot Water Only (Energy C Model Only)
- Check Resistance On The Heating Flow & Return NTC Thermistors To Ensure Accurate Temperature Monitoring (Should Read 12K ohms @ 20C)
|
Fault Code F22 |
Low System Water Pressure - Less Than 0.3bar (Energy C & S Models Only) |
- Water Leak Within The Boiler
- Water Leak Within The System
- The Pressure Relief Valve Has Activated Due To An Expansion Related Issue - Check Expansion Vessel & Heating System Water Volume
|
Fault Code F23 |
Maximum Temperature Differential Across The Heating Flow & Return Has Been Reached (35 Degrees C) |
- Inadequate Pump Operation
- Blockage Or Air Lock Within The Appliance (No Water Movement)
- Blockage Or Air Lock In The Heating System (No Water Movement)
- Check Domestic Hot Water Heat Exchanger and Domestic Hot Water Heat Exchanger Filter For Debris If Fault Occurs On Hot Water Mode Only (Energy C Model Only)
- Check Resistance On The Heating Flow & Return NTC Thermistors To Ensure Accurate Temperature Monitoring (Should Read 12K ohms @ 20C)
|
Fault Code F24 |
Water Circulation Fault (Temperature Rise Greater Than 10 Degrees Celcius Per Second) |
- Inadequate Pump Operation
- Isolation Valves Closed Under The Appliance (Energy C & S Models Only)
- Blockage Or Air Lock Within The Appliance (No Water Movement)
- Blockage Or Air Lock In The Heating System (No Water Movement)
- Check Domestic Hot Water Heat Exchanger and Domestic Hot Water Heat Exchanger Filter For Debris If Fault Occurs On Hot Water Mode Only (Energy C Model Only)
- Check Resistance On The Heating Flow & Return NTC Thermistors To Ensure Accurate Temperature Monitoring (Should Read 12K ohms @ 20C)
|
Fault Code F25 |
Flue Gas Temperature Too High (Not Applicable To UK Model Boilers) |
|
Fault Code F27 |
Incorrect Flame Detection Fault (Flame Detection Even Though The Gas Valve Is Off) |
- Damage On The Electrode Or The Ignition Lead
- Moisture Present On The Electronics
- Fault On The Spark Generator
|
Fault Code F28 |
Ignition Failure |
- Insufficient Inlet Working Gas Pressure To The Appliance
- Flue Problem
- Bad Earth Connection
- Incorrect Gas Valve Adjustment
- Debris Within The Heat Engine (Burner Etc)
- Electrode Or Ignition Lead Fault
- Spark Generator Fault
- Faulty Gas Valve
|
Fault Code F29 |
Flame Failure During Operation |
- Insufficient Inlet Working Gas Pressure To The Appliance
- Flue Problem
- Incorrect Gas Valve Adjustment
- Debris Within The Heat Engine (Burner Etc)
- Electrode Or Ignition Lead Issue
- Spark Generator Fault
- Faulty Gas Valve
|
Fault Code F32 |
Air Fault – (Fan Or Flue) |
- Blockage In The Flue System
- Fan Rotation Speed Incorrect (Power To Fan But Fan Not Running)
- Loose Connection On The Wiring Harness Between The Fan And The Main PCB
|
Fault Code F33 |
Air Pressure Switch Fault – (Not Applicable To UK Market) |
|
Fault Code F49 |
eBus Voltage Error (Glow Worm Heating Controls Only) |
- Overload On eBus Connection On Main PCB
- Check External Glow Worm eBus Heating Controls
- Check Wiring Between Glow Worm eBus Controls And The Main PCB
- Check For Correct eBus Output Voltage (22vdc) From Main PCB
|
Fault Code F61 |
Gas Valve Fault |
- Loose Or Damaged Electrical Connection Between The Gas Valve & The Main PCB
|
Fault Code F62 |
Gas Valve Closure Fault |
- Flame Presence Still Detected After A Demand Has Ceased Due To The Gas Valve Not Shutting Down Correctly (Gas Valve Fault - Passing)
- Fault On Electronics (Power To The Gas Valve With No Demand)
|
Fault Code F63 |
Main PCB Memory Fault |
- Loose Or Damaged Electrical Connection On The Main PCB
- The User Interface PCB Has Not Been Set Up Correctly By The Service Engineer (Incorrect Product Code Has Been Entered)
|
Fault Code F64 |
Rapid Fluctuation Of Heating Flow Or Return NTC Thermistors Due To Electrical Errors |
- Loose Or Damaged Electrical Connections Between The Flow Or Return NTC Thermistors And The Main PCB
- Inconsistent Resistance On Heating Flow Or Heating Return NTC Thermistor Due To Thermistor Failure
|
Fault Code F65 |
Main PCB Temperature Too High |
- Mains Input Voltage Problem
- Damaged Or Loose Electrical Connection On The Main PCB
|
Fault Code F67 |
Flame Signal Fault On The Main PCB |
- Damaged Or Loose Electrical Connection On The Main PCB
- Mains Input Voltage Problem (Reverse Polarity, Bad Earth Etc)
|
Fault Code F68 |
Fluctuation Of Flame Signal |
- Insufficient Inlet Working Gas Pressure To The Appliance
- Flue Problem
- Incorrect Gas Valve Adjustment (Poor Combustion)
- Debris Within The Heat Engine (Burner Etc)
- Electrode Or Ignition Lead Fault
- Spark Generator Fault
- Faulty Gas Valve
|
Fault Code F70 |
Incompatible Software |
- Replacement User Interface PCB Has Not Been Set Up Correctly By The Service Engineer
|
Fault Code F71 |
Heating Flow NTC Thermistor Disconnected Or Defective (No Temperature Change When Burner Lit) |
- Heating Flow NTC Thermistor Is Not Connected To The Flow Pipe On The Main Heat Exchanger Correctly
- Defective Heating Flow NTC Thermistor
|
Fault Code F72 |
Permanent Temperature Difference Between Heating Flow & Return NTC Thermistors (Thermistor Error) |
- The Heating Flow NTC Thermistor Is Reading The Incorrect Resistance (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Flow NTC Thermistor And The Main PCB
- The Heating Return NTC Thermistor Is Reading The Incorrect Resistance (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Return NTC Thermistor And The Main PCB
- The Thermistors Have Been Reversed (Connected To The Wrong Pipes)
|
Fault Code F73 |
Low Water Pressure Sensor Fault (Energy C & S Models Only) |
- Broken, Loose Or Damp Electrical Connection On The Wiring Harness Between The Low Water Pressure Sensor And The Main PCB
- Low Water Pressure Sensor Fault
|
Fault Code F74 |
Low Water Pressure Sensor Fault (Energy C & S Models Only) |
- Broken, Loose Or Damp Electrical Connection On The Wiring Harness Between The Low Water Pressure Sensor And The Main PCB
- Low Water Pressure Sensor Fault
|
Fault Code F75 |
Low Water Pressure Sensor Fault Or Pump Proving Issue (Energy C & S Models Only) |
- Low Water Pressure Sensor Faulty Or Blocked With System Debris
(Water Pressure Sensor Needs To See A 50 mBar (0.05 Bar) Pressure Increase On Pump Start Within 10 Seconds)
- Flow Filter Blocked With Debris (Energy C Models Only)
- Expansion Vessel Air Charge Insufficient
|
Fault Code F76 |
Thermal Fuse Failure - Heat Exchanger Has Reached 160 Degrees C (Not Applicable To UK Models) |
|
Fault Code F77 |
External Glow Worm Condensate Pump Fault |
- Fault With Glow Worm Condensate Pump Or Associated Wiring
|
Fault Code F78 |
Compatibility Error Between The Boiler And The Glow Worm eBUS System Controls |
- The Glow Worm eBUS System Controls Are Not Compatible With The Boiler
- Wiring Fault Between The Boiler And The Glow Worm eBUS System Controls
- Glow Worm eBUS System Controls Fault
- Loose Or Damaged Wiring Connection On The Main PCB
|
Fault Code F83 |
Insufficient Temperature Increase Once Burner Is Lit |
- Low System Water Pressure
- Flow Or Return NTC Thermistors Out Of Calibration (Should Read 12Kohms @ 20C) Or Not Connected To Pipework Correctly
- Damaged Or Loose Connections On The Wiring Loom Between The NTC Thermistors And The Main PCB
- Low Heat Input Into The Heat Exchanger – Poor Thermal Performance Caused By Low Gas Rate, Incorrectly Adjusted Gas Valve, Or Restriction/Poor Heat Transfer Within The Combustion Chamber
|
Fault Code F84 |
Permanent Temperature Difference Between Heating Flow & Return NTC Thermistors (Thermistor Error) |
- The Heating Flow NTC Thermistor Is Reading The Incorrect Resistance (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Flow NTC Thermistor And The Main PCB
- The Heating Return NTC Thermistor Is Reading The Incorrect Resistance (Should Read 12Kohms @ 20C)
- Wiring Harness Fault Or Connection Error Between The Heating Return NTC Thermistor And The Main PCB
- The Thermistors Have Been Reversed (Connected To The Wrong Pipes)
|
Fault Code F85 |
Flow Or Return NTC Thermistor Fault |
- The Flow & Return NTC Thermistors Are Both Connected To The Same Pipe (Reading The Same Temperature)
- Faulty Flow Or Return NTC Thermistor
|
Fault Code F86 |
Overheat Thermostat From 3rd Party Underfloor Heating Control Has Activated (If Fitted) |
- Check For Circulation Issues On Any Underfloor Heating Circuits
- If No 3RD Party Underfloor Overheat Thermostat Is Fitted To The Boiler, Check That The Link Wire Is Fitted Into The “B.off” Connection On Terminal X41 On The Main PCB
|
Fault Code F87 |
Electrode Fault |
- Faulty Ignition Electrode Or Ignition Lead
|
Fault Code F88 |
Electrical Fault On The Gas Valve Circuit |
- Loose Or Damaged Connection On The Wiring Harness Between The Main PCB and The Gas Valve
- Faulty Gas Valve (Short Circuit)
|
Fault Code F89 |
Electrical Fault On The Pump (Energy C & S Models Only) |
- Loose Or Damaged Connection On The Wiring Harness Between The Pump and The Main PCB
- Faulty Pump (Short Circuit)
|
Fault Code F91 |
Domestic Hot Water Cylinder NTC Thermistor Fault (Not Applicable To This Appliance) |
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