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CXI / SXI / HXI / BG330 Fault Codes

Fault Code

Fault Description

Possible Causes

Fault Code F1

 

Ignition Failure

 
  • Insufficient Inlet Working Gas Pressure At The Appliance
  • Flue Problem
  • Condensate Blockage
  • Spark Generation Issue
  • Incorrect Gas Valve Adjustment
  • Flame Rectification Issue
  • Poor Combustion
  • Combustion Door Seal Leak
  • Software Error On The Main PCB Or The User Interface PCB

 

Fault Code F2

Air Fault

 
  • Fan Fault
  • Fan Wiring Harness Fault
  • No Power To The Fan From The Main PCB
  • No Power To The Fan From The DC Fan Transformer (Early Models Only)
  • Replacement Main PCB Not Fitted Correctly By Service Engineer (DC Fan Transformer Bridging Card Not Fitted Correctly)

 

Fault Code F3

Air Fault
  • Fan Fault
  • Fan Wiring Harness Fault
  • No Power To The Fan From The Main PCB
  • No Power To The Fan From The DC Fan Transformer (Early Models Only)
  • Replacement Main PCB Not Fitted Correctly By Service Engineer (DC Fan Transformer Bridging Card Not Fitted Correctly)

 

 

Fault Code F4

Ignition Failure Or Flame Sensing Fault

 
  • Insufficient Inlet Working Gas Pressure At The Appliance
  • Flue Problem
  • Condensate Blockage
  • Spark Generation Issue
  • Incorrect Gas Valve Adjustment
  • Lack Of Flame Rectification
  • Poor Combustion/Flame Picture
  • Combustion Door Seal Leak
  • Software Error On The Main PCB Or The User Interface PCB
  • Spark Generator Fault

 

Fault Code F5

Overheat Fault

 
  • The Overheat Thermostat Has Activated In The Appliance Due To Poor Circulation (115C)
  • Pump Not Running
  • Air Lock Within The Boiler Or The System
  • Blockage Within The Boiler Or The System
  • Heating Return Filter Blocked In Appliance (Cxi & Sxi Models Only)
  • System Design Issue
  • No Permanent Live Wired Into The Appliance Causing No Pump Overrun (Hxi Model Only)
  • Pump Not Wired Directly Into The Appliance (Hxi Model Only)
  • Insufficient System Bypass
  • NTC Thermistor Out Of Calibration (Should Read 12Kohms @ 20C)

 

Fault Code F6

Heating Flow Thermistor Fault

 
  • The Heating Flow NTC Thermistor Has Gone Open Circuit          (Should Read 12Kohms @ 20C)
  • Wiring Harness Fault Or Connection Fault Between The Heating Flow Thermistor And The Main PCB
  • Flow & Return Piped Up The Wrong Way Round (Hxi Model Only)
  • External System Pump Circulating The Wrong Way Around The System (Hxi Model Only)

 

Fault Code F7

Domestic Hot Water Thermistor Fault (Cxi Model Only)

 
  • The Domestic Hot Water NTC Thermistor Has Gone Open Circuit (Should Read 12Kohms @ 20C)
  • Wiring Harness Or Connection Fault Between The Domestic Hot Water Thermistor & The Main PCB

 

Fault Code F8

Not Applicable To This Appliance
  • If This Code Appears It Is Software Error On The Main PCB Or The User Interface PCB

 

Fault F9

Multiple Errors

 
  • Low Water Pressure Sensor Fault
  • Overheat Thermostat Has Activated (Early Models Only)
  • NTC Thermistor Fault (Should Read 12Kohms @ 20C)
  • The Fuse Has Blown In The DC Fan Transformer Unit (Early Models Only)
  • Incompatible Software on Main PCB or User Interface PCB
  • Circulation Problem (If F9 Flashes On The Display & Then Resets Itself)
  • Low Voltage Component Failure
  • Connection Fault On The Low Voltage Component Wiring Loom
  • Replacement User Interface PCB Has Not Been Set Up Correctly By The Service Engineer

 

Fault Code F10

Heating Return Thermistor Fault

 
  • The Heating Return NTC Thermistor 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 F11

Software Error On The Main PCB

 
  • Main PCB Fault
  • Loose Wiring Connection On The Main PCB
  • Domestic Hot Water Flow Sensor Fault (Cxi Model Only)

 

Fault Code F12

Software Errors

 
  • Fault On The Main PCB
  • Fault On The User Interface PCB
  • Faulty Domestic Hot Water Flow Sensor (Cxi Model Only)
  • Faulty Water Pressure Sensor (Cxi & Sxi Models Only)
  • Wiring Loom Fault

Fault Code F13

Software Or Electrical Error

 
  • Main PCB Fault
  • User Interface PCB Fault
  • Loose Or Damaged Connection On The Wiring Loom
  • Insufficient Earth
  • Low Voltage Component Failure
  • Water Leak On The Diverter Motor (Cxi Model Only)

 

Fault Code F14

 

The Flow Pipe On The Main Heat Exchanger Is Greater Than 95 Degrees

 
  • Blockage Or Air Lock In The Appliance
  • Pump Not Running
  • System Circulation Fault
  • Blocked Domestic Hot Water Heat Exchanger (Cxi Model Only)
  • Heating Flow NTC Thermistor Out Of Calibration (Should Read 12Kohms @ 20C)
  • External System Pump Not Wired Into The Appliance Causing No Pump Over-Run (Hxi Model Only)

 

Fault Code F15

Not Applicable To This Appliance

 

 

Fault Code F16

Flame Detection Fault (Flame Presence For More Than 5 Seconds After Burner Stop)

 
  • Gas Valve Fault – (Flame Still Present After Demand Has Ceased)
  • Software Fault On The Main PCB Or The Spark Generator Unit

 

Fault Code F17

Incoming Power Supply <170V

 
  • Incoming Power Supply Or Polarity Issue
  • Fuse Blown In The DC Fan Transformer (Early Models Only)
  • Main PCB Fault
  • Incompatible Software (Incorrect PCB Fitted To Appliance)

 

Fault Code F18

User Interface PCB Fault

 
  • Check Cable Connection Between Main PCB & User Interface PCB
  • User Interface PCB Fault

 

Fault Code F19

Insufficient Temperature Rise On Heating Flow Pipe After Ignition

 
  • Heating Flow NTC Thermistor Disconnected  From The Flow Pipe Off The Main Heat Exchanger
  • Diverter Valve Passing Into The Central Heating Circuit During Hot Water Demand (Cxi Model Only)
  • Poor Heat Input Into The Heat Engine Causing Insufficient Temperature Rise (Low Inlet Working Gas Pressure, Gas Valve Incorrectly Adjusted, Burner Issue Etc)
  • Domestic Hot Water Flow Rate Too Excessive

Fault Code F20

Incompatible Software

 
  • Wrong Main PCB Fitted Into The Appliance
  • Wrong User Interface PCB Fitted Into The Appliance
  • Wiring Harness Fault Between Main PCB & User Interface PCB
  • Replacement User Interface PCB Has Not Been Set Up Correctly By Service Engineer

Fault Code F21

Not Applicable To This Appliance

 

 

Fault Code F22

Not Applicable To This Appliance

 

 

Fault Code F23

Not Applicable To This Appliance

 

 

Fault Code F24

Heating Return Is Greater Than 90 Degrees

 
  • The Temperature On The Return Pipe On The Main Heat Exchanger Has Reached Over 90 Degrees
  • Blockage Or Air Lock Within The Appliance
  • System Design Fault
  • System Circulation Fault
  • Heating Pump Not Operating Correctly
  • Heating Return NTC Thermistor Is Out Of Calibration (Should Read 12Kohms @ 20C)
  • Boiler Piped Up The Wrong Way Round (Hxi Models)

 

Fault Code F25

Flow Temperature Rise Too High During Operation

 
  • The Temperature On The Main Heat Exchanger Flow Pipe Has Risen By 5 Degrees Per Second Due To A Blockage Or An Air Lock In The Appliance Or The System
  • Pump Not Running
  • Return Filter Blocked
  • Heating Flow NTC Thermistor Is Out Of Calibration (Should Read 12Kohms @ 20C)

Fault Code F26

Maximum Temperature Differential Has Been Exceeded (>35 Degrees Celcius across Flow & Return)

 
  • System Design Fault
  • Pump Not Running
  • Air In The System Restricting Water Movement
  • Debris In The System Restricting Water Movement
  • The Heating Return NTC Thermistor Is Out Of Calibration (Should Read 12Kohms @ 20C)

 

2.7 Bar Or More Flashing On Display (Cxi & Sxi Models Only)

High Pressure Fault

 
  • The Pressure In The Appliance Has Reached Over 2.7 Bar
  • The Filling Loop Has Been Left On Or Is Passing
  • Split Domestic Hot Water Heat Exchanger (Cxi Model Only)
  • Central Heating System Is To Large For The Appliance
  • Expansion Vessel Issue (Insufficient Air Charge Or Faulty Vessel)
  • Expansion Vessel Supply Hose Is Blocked
  • Incorrect Pressure Reading Being Shown Due To A Water Pressure Sensor Fault

0.5 Bar Or Less Flashing On Display (Cxi & Sxi Models Only)

 

Low Pressure Fault

 
  • The Pressure In The Appliance Has Dropped To Below 0.5Bar
  • Water Leak On The Boiler
  • Water Leak On The System
  • Incorrect Pressure Reading Being Shown Due To A Water Pressure Sensor Fault

 

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