HERE YOU WILL FIND THE FAULT CODES FOR THE GLOW WORM ULTRACOM CXI 2 BOILER, JUST CHECK THE FAULT CODE DISPLAYED ON THE BOILER AGAINST THE LIST. PLEASE NOTE THAT YOU MUST BE GAS SAFE REGISTERED TO WORK ON GAS APPLIANCES, PLEASE CALL US IF IN DOUBT AND WE WILL SEND A ENGINEER TO REPAIR IT.




FAULT   CODES                             DESCRIPTION                         CAUSE                             SOLUTION


F00                         

Flow heating temperature sensor fault   

  Sensor open circuit • Check the sensor’s connections.                                                                                                                                            

• Check the wiring harness.
• Check the sensor.
 

01   Return heating temperature sensor fault


Return heating temperature sensor
disconnected


F10 Flow heating temperature sensor fault Sensor short-circuit


F11 Return heating temperature sensor fault


Return heating temperature sensor
shorted.
F20 Overheating fault


Overheating safety device activated
(97°C)
• Check the operation of the pump.
• Check the wiring harness.
• Check that the flow and return heating isolation
valves are open.


F22 Water pressure of the installation (<0.3 bar)


Return water valve closed
Pump disconnected
Leak in the installation
• Fill the installation.
• Purge the installation.
• Check the pump connections.
• Check the flow and return heating sensor
connections.
• Check that there are no leaks.


F23
Maximum temperature difference reached
between return and flow heating


Water circulation fault
• Check the flow and return heating sensor
connection.
• Check the pump speed.
F24 Water circulation fault


Malfunction of the pump (excessively
rapid temperature increase)
• Check that the flow and return heating isolation fault
codes

F26 Fault in gas valve motor.

Disconnected or defective cables
• Check the gas valve connections.
• Check the operation of the gas valve.
• Check the operation of the condensate pump (option).


F27 Flame detection fault.

 Abnormal flame detection
• Check the flame detection electrode.
• Check the main board.
• Check the igniter unit.
F28 Ignition fault No return gas / Insufficient gas flow


Gas valve incorrectly adjusted
Defective firing electrode and flame
control / Defective igniter unit
• Check the return gas circuit (gas valve open).
• Check the observe the flame picture and check
the CO2
setting.
• Check the igniter unit connections.
• Check the state of the electrode (corrosion).


F29 Loss of flame during operation


F32 Incorrect air pressure Incorrect fan speed.


• Check the entire flue system.
• Check the fan’s electrical connections.


F49 EBUS voltage fault


Fault in EBUS line
Short circuit in EBUS connector
• Check that the eBus controls are fitted and wired
correctly.


F61
Fault in the main board


Gas valve command fault
• Check the main boards connections.
• Check the main board.
• Check the appliance DSN number is correct.
• Reset the appliance.


F62 Gas valve closure fault


F63 Fault in the main board memory


F64
Rapid fluctuation of return or flow
heating sensor.


F65 Excessive main board temperature


F67 Flame signal fault in the main board


F68 Fluctuation of flame signal


No return gas / Insufficient gas flow
Gas valve incorrectly adjusted
Defective firing electrode and flame
control / Defective igniter unit
• Check the return gas circuit (gas valve open).
• Check the observe the flame picture and check
the CO2
setting.
• Check the igniter unit connections.
• Check the state of the electrode (corrosion).

F70

User interface incompatible with the main
board

Incorrect product code
• Check that the appliance DSN code on the screen
matches the product code of the nameplate (in the
event of a fault and the appliance DSN does not
appear, consult menu.d.93 reserved for the code).
• Check the boards reference.


F71 Flow heating temperature sensor fault


Flow heating temperature sensor
unclipped or defective (no
temperature variation)
• Check the sensor connections.
• Make sure that the sensor is clipped to the tube.


F72
Permanent temperature difference between
flow and return heating sensors


Mismatch between the flow and return
heating temperatures (permanent
difference)
• Check temperature sensors connections.
• Replace faulty sensors.


F73 Heating circuit pressure sensor fault The sensor is shorted or disconnected.
• Check the sensor’s connections.


F74 Heating circuit pressure sensor fault Fault in pressure sensor
• Check the sensor.


F76 Thermal fuse fault


Thermal fuse disconnected
Defective thermal fuse
• Check the fuses connections.
• Replace the heat exchanger.


F77 Fault in gas valve motor.


Defective gas valve.
Defective condensate pump (option)
• Check the gas valve connections.
• Check the operation of the gas valve.
• Check the operation of the condensate pump (option).


F83
No water in the installation : the temperature
does not increase when the burner is lit


Return water valve closed
Pump disconnected
Leak in the installation
• Fill the installation.
• Purge the installation.
• Check the pump connections.
• Check the flow and return heating sensor
connections.
• Check that there are no leaks.


F84
Permanent temperature difference between
flow and return heating sensors


Inverted or disconnected flow and
return heating temperature sensors
Defective temperature sensors
• Check temperature sensors connections.
• Replace faulty sensors.


F85 Flow and return heating sensors fault


Flow and return heating temperature
sensor connected to same tube
• Check temperature sensors connections.


F86 Underfloor heating contact fault


Floor heating contact open
Sensor disconnected or defective
• Check the sensor connections.
• Check that the sensor is connected to the main
board and the shunt is removed.
Err User interface fault Defective user interface
• Check connection from user interface PCB to main
PCB.
• Replace user interface
valves are open