Glow-worm boiler fault codes & error codes with advice & solutions
Glow-worm is a major player in the energy sector in the United Kingdom. They began building boilers in Derbyshire in the 1930s and have since grown to become one of the UK’s major providers of sustainable energy solutions. Glow-worm to provide ‘excellent quality, reliability, and durability.
The goal of this blog, however, is to assist you in identifying the issues that your boiler may be experiencing, as well as provide a list of all Glow-worm boiler fault codes and Glow-worm error codes, so that you may feel a bit less anxious about your boiler.
Glow-worm offers a variety of gas boiler models, including combi boilers, system boilers, and ordinary heat-only boilers, in a variety of sizes and styles whichever according to your requirement and need Glow-worm, which began manufacturing boilers in 1934 at the Derwent Foundry in Derbyshire, are dedicated for providing durable and highly efficient boilers to their customers for the past 80 years. Glow-worm was acquired by the Vaillant Group, Europe’s second-largest heating manufacturer, in 2001.
List of Glow Worm Boiler Fault Codes and Error Codes
| Fault Code |
Possible Cause |
| F.00 |
Fault: Flow temperature sensor |
| F.01 |
Fault: Return temperature sensor |
| F.10 |
Short circuit: Flow temperature sensor |
| F.11 |
Short circuit: Return temperature sensor |
| F.12 and F.91 |
Short circuit: Cylinder temperature sensor |
| F.13 |
Short circuit: Domestic hot water cylinder temperature sensor |
| F.20 |
Safety switch-oft. The overheating temperature reached |
| F.22 |
Safety switch-oft. Low water pressure in the boiler |
| F.23 |
Safety switch-oft. Temperature difference too great (NTC1/NTC2) |
| F.24 |
Safety switch-oft. The temperature rises too fast |
| F.25 |
Safety switch-off. Flue gas temperature too high |
| F.27 |
Safety switch-off. Fault in flame detection |
| F.28 |
Fault: Ignition unsuccessful when starting up |
| F.29 |
Fault: Flame loss |
| F.32 |
Fan frost protection function active: Fan speed outside the tolerance values |
| F.33 |
Fan frost protection function active: Air pressure switch fault |
| FA9 |
eBUS fault: Voltage too low |
| F.61 |
Fault: Gas valve control system |
| F.82 |
Fault: Gas valve switch-off control |
| F.83 |
Fault: EEPROM |
| F.64 |
Fault: Electronics/sensor/analogue-to-digital converter |
| F.85 |
Fault: Electronics temperature too high |
| F.67 |
Value sent back by ASIC is incorrect (flame slgnal) |
| F.88 |
Fault: Unstable flame (analogue input) |
| F.70 |
Invalid product code (DSN) |
| F.71 |
Fault: Flow/return temperature sensor |
| F.72 |
Fault: Deviation in the water pressure sensor/return temperature sensor |
| F.73 |
Fault: Water pressure sensor not connected or has short-circuited |
| F.74 |
Fault: Electrical problemin the water pressure sensor |
| F.75 |
Fault: Pressure sensor |
| F.78 |
The safety cut-out in the primary heat exchanger is defective |
| F.77 |
Fault: Condensate or smoke |
| F.78 |
Interruption to DHW outlet sensor at external controller |
| F.83 |
Fault: Burner temperature sensor |
| F.84 |
Fault: Flow/return temperature sensor |
| F.85 |
Fault: Temperature sensor |
| F.88 |
Fault: Underfloor heating contact |
| F.87 |
Fault: Electrodes |
| F.88 |
Fault: Gas valve |
| F.89 |
Fault: Pump |
| Connection |
No communication between the PCB and the user interface |
Betacom Range
| Fault Code |
Possible Cause |
| Red LED on |
Lockout – Low water pressure, Make sure pressure is above 1.5bar, reset boiler |
| Red LED flashing |
DHW temperature control knob in service position – Turn DHW control knob into temperature range |
| Red LED flashing |
Overheat – Check both overheat stats |
| Yellow LED flashing |
Error – Wait for a minimum of 30 seconds after turning the DHW control knob into the temperature range and the CH temperature control knob into power (reset position) before turning into either summer or temperature position. |
| Yellow LED on |
Flame present on the burner |
| Green LED on |
Boiler ready for operation |
| Green LED off |
No power to the boiler – Check for 230volts into the appliance, check the fuse on pcb |
| Green LED flashing |
Boiler in stand-by – Reset position |
Betacom A Range
| Fault Code |
Possible Cause |
| F00 |
Flow heating temperature sensor fault |
| F01 |
Return heating temperature sensor fault |
| F10 |
Flow heating temperature sensor fault |
| F11 |
Return heating temperature sensor fault |
| F20 |
Overheating fault |
| F22 |
Low water pressure |
| F23 |
Water circulation fault |
| F24 |
Water circulation fault |
| F26 |
Fault in gas valve |
| F27 |
Flame detection fault |
| F28 |
Ignition fault |
| F29 |
Loss of flame during operation |
| F32 |
Incorrect air pressure |
| F49 |
EBUS voltage fault |
| F61 |
Fault in the mainboard |
| F62 |
Fault in the mainboard |
| F63 |
Fault in the mainboard |
| F64 |
Fault in the mainboard |
| F65 |
Fault in the mainboard |
| F67 |
Fault in the mainboard |
| F68 |
Fluctuation of flame signal |
| F70 |
User interface incompatible with the mainboard |
| F71 |
Flow heating temperature sensor fault |
| F72 |
Permanent temperature difference between flow and return heating sensors |
| F73 |
Heating circuit pressure sensor fault |
| F74 |
Heating circuit pressure sensor fault |
| F76 |
Thermal fuse fault |
| F77 |
Fault in gas valve motor |
| F83 |
No water in the installation |
| F84 |
Permanent temperature difference between flow and return heating sensors |
| F85 |
Flow and Return heating sensor fault |
| F86 |
Underfloor heating contact fault |
| Err |
User interface fault |
Betacom C Range
| Fault Code |
Possible Cause |
| Temperature 30 flashing |
Fault on CH thermistor |
| Temperature 40 flashing |
Fault on DHW thermistor |
| Temperature 50 flashing |
Fault on outside sensor |
| Temperature 60 flashing |
Low system pressure |
| Temperature 70 flashing |
Fault on APS |
| Temperature 80 flashing |
Overheat open circuit |
| Temperature 90 flashing |
Flame or gas failure |
Compact E Range
| Fault Code |
Possible Cause |
| No DHW |
Check dhw microswitch |
| No C/H |
Check the microswitch if dhw demand-led is lit |
| No C/H but the boiler is firing |
Check divertor motor and cartridge |
| Boiler locks out within 10 seconds |
Check pump proving switch, an air pressure switch and overheat stat |
| Poor burner pressure |
Check burner pressure/ignition adjustment pots on PCB |
Compact S Range
| Fault Code |
Possible Cause |
| No DHW |
Check external controls, Please test for 230V on switch live to contact |
| No C/H |
Check external controls, Please test for 230V on switch live contact |
| No C/H or DHW |
Check external controls, Please test for 230V on switch live contact |
| Boiler locks out within 10 seconds |
Check pump proving switch, an air pressure switch and overheat stat |
| Poor burner pressure |
Check burner pressure/ignition adjustment pots on PCB |
CI Range Boiler
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F2 |
Fan/APS |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F8 |
Tank thermistor (N/A For this appliance) |
| F9 |
Water pressure sensor fault (please contact GW technical department for further information |
| F10 |
Central return flow thermistor |
| F11 |
Mainboard connection fault |
| F12 |
Connection fault between the main pcb and display pcb |
| F13 |
Main pcb connection fault |
| F14 |
Central heating flow temperature > 95 degrees |
| F15 |
Gas valve stepper motor fault |
| F16 |
Flame detection fault |
| F17 |
Power supply is less than 170v |
| F18 |
User interface fault |
| F19 |
Central heating thermistor unplugged |
| F20 |
Software incompatibility |
CI Plus Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F2 |
Fan/APS |
| F3 |
Air fault |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F8 |
Tank thermistor (N/A For this appliance) |
| F9 |
Water pressure sensor fault (please contact GW technical department for further information |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F12 |
Connection fault between the main pcb and display pcb |
| F13 |
Main pcb connection fault |
| F14 |
Central heating flow temperature > 95 degrees |
| F15 |
Gas valve stepper motor fault |
| F16 |
Flame detection fault |
| F17 |
Power supply is less than 170v |
| F18 |
User interface fault |
| F19 |
Central heating thermistor unplugged |
| F20 |
Software incompatibility |
CXI Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F2 |
Fan |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F8 |
Tank thermistor (N/A For this appliance) |
| F9 |
Water pressure sensor fault (please contact GW technical department for further information |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F12 |
Connection fault between main pcb and display pcb |
| F13 |
Main pcb connection fault |
| F14 |
Central heating flow temperature > 95 degrees |
| F15 |
Gas valve stepper motor fault |
| F16 |
Flame detection fault |
| F17 |
Power supply is less than 170v |
| F18 |
User interface fault |
| F19 |
Central heating thermistor unplugged |
| F20 |
Software incompatibility |
| F24 |
Central heating return temperature > 90 degrees |
| F25 |
Poor circulation |
| F26 |
Poor circulation |
Flexicom CX Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F9 |
Water pressure sensor fault, blocked flow filter or pump fault |
| F10 |
Central return flow thermistor |
| F11 |
Flow and or return thermistor fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F24 |
Central heating return temperature > 90 degrees |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
Flexicom HX Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F9 |
Low water pressure Sensor |
| F10 |
Central return flow thermistor |
| F11 |
Flow and or return thermistor fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
Flexicom SX Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F9 |
Low water pressure Sensor |
| F10 |
Central return flow thermistor |
| F11 |
Flow and or return thermistor fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
HXI Range Boiler
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F2 |
Fan |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F8 |
Tank thermistor (N/A For this appliance) |
| F9 |
Earlier models only (please contact GW technical department for further information) |
| F10 |
Central return flow thermistor |
| F11 |
Mainboard connection fault |
| F12 |
Connection fault between the main pcb and display pcb |
| F13 |
Main pcb connection fault |
| F14 |
Central heating flow temperature > 95 degrees |
| F16 |
Flame detection fault |
| F17 |
Power supply is less than 170v |
| F18 |
User interface fault |
| F19 |
Central heating thermistor unplugged |
| F20 |
Software incompatibility |
| F24 |
Central heating return temperature > 90 degrees |
| F25 |
Poor circulation |
| F26 |
Poor circulation |
SI Range Boiler
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F2 |
Fan/APS |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F8 |
Tank thermistor (N/A For this appliance) |
| F9 |
Water pressure sensor fault (please contact GW technical department for further information) |
| F10 |
Central return flow thermistor |
| F11 |
Mainboard connection fault |
| F12 |
Connection fault between the main pcb and display pcb |
| F13 |
Main pcb connection fault |
| F14 |
Central heating flow temperature > 95 degrees |
| F15 |
Gas valve stepper motor fault |
| F16 |
Flame detection fault |
| F17 |
Power supply is less than 170v |
| F18 |
User interface fault |
| F19 |
Central heating thermistor unplugged |
| F20 |
Software incompatibility |
SXI Range Boiler
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F2 |
Fan |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F8 |
Tank thermistor (N/A For this appliance) |
| F9 |
Water pressure sensor fault (please contact GW technical department for further information) |
| F10 |
Central return flow thermistor |
| F11 |
Mainboard connection fault |
| F12 |
Connection fault between the main pcb and display pcb |
| F13 |
Main pcb connection fault |
| F14 |
Central heating flow temperature > 95 degrees |
| F15 |
Gas valve stepper motor fault |
| F16 |
Flame detection fault |
| F17 |
Power supply is less than 170v |
| F18 |
User interface fault |
| F19 |
Central heating thermistor unplugged |
| F20 |
Software incompatibility |
| F24 |
Central heating return temperature > 90 degrees |
| F25 |
Poor circulation |
| F26 |
Poor circulation |
Ultracom2 CXI Range
| Fault Code |
Possible Cause |
| F00 |
Flow heating temperature sensor fault |
| F01 |
Return heating temperature sensor fault |
| F10 |
Flow heating temperature sensor fault |
| F11 |
Return heating temperature sensor fault |
| F20 |
Overheating fault |
| F22 |
Low water pressure |
| F23 |
Water circulation fault |
| F24 |
Water circulation fault |
| F26 |
Fault in gas valve |
| F27 |
Flame detection fault |
| F28 |
Ignition fault |
| F29 |
Loss of flame during operation |
| F32 |
Incorrect air pressure |
| F49 |
EBUS voltage fault |
| F61 |
Fault in the mainboard |
| F62 |
Fault in the mainboard |
| F63 |
Fault in the mainboard |
| F64 |
Fault in the mainboard |
| F65 |
Fault in the mainboard |
| F67 |
Fault in the mainboard |
| F68 |
Fluctuation of flame signal |
| F70 |
User interface incompatible with the mainboard |
| F71 |
Flow heating temperature sensor fault |
| F72 |
Permanent temperature difference between flow and return heating sensors |
| F73 |
Heating circuit pressure sensor fault |
| F74 |
Heating circuit pressure sensor fault |
| F76 |
Thermal fuse fault |
| F77 |
Fault in gas valve motor |
| F83 |
No water in the installation |
| F84 |
Permanent temperature difference between flow and return heating sensors |
| F85 |
Flow and Return heating sensor fault |
| F86 |
Underfloor heating contact fault |
| Err |
User interface fault |
Ultracom2 SXI Range
| Fault Code |
Possible Cause |
| F00 |
Flow heating temperature sensor fault |
| F01 |
Return heating temperature sensor fault |
| F10 |
Flow heating temperature sensor fault |
| F11 |
Return heating temperature sensor fault |
| F20 |
Overheating fault |
| F22 |
Low water pressure |
| F23 |
Water circulation fault |
| F24 |
Water circulation fault |
| F26 |
Fault in gas valve |
| F27 |
Flame detection fault |
| F28 |
Ignition fault |
| F29 |
Loss of flame during operation |
| F32 |
Incorrect air pressure |
| F49 |
EBUS voltage fault |
| F61 |
Fault in the mainboard |
| F62 |
Fault in the mainboard |
| F63 |
Fault in the mainboard |
| F64 |
Fault in the mainboard |
| F65 |
Fault in the mainboard |
| F67 |
Fault in the mainboard |
| F68 |
Fluctuation of flame signal |
| F70 |
User interface incompatible with the mainboard |
| F71 |
Flow heating temperature sensor fault |
| F72 |
Permanent temperature difference between flow and return heating sensors |
| F73 |
Heating circuit pressure sensor fault |
| F74 |
Heating circuit pressure sensor fault |
| F76 |
Thermal fuse fault |
| F77 |
Fault in gas valve motor |
| F83 |
No water in the installation |
| F84 |
Permanent temperature difference between flow and return heating sensors |
| F85 |
Flow and Return heating sensor fault |
| F86 |
Underfloor heating contact fault |
| Err |
User interface fault |
Ultracom2 35 Store
| Fault Code |
Possible Cause |
| F00 |
Flow heating temperature sensor fault |
| F01 |
Return heating temperature sensor fault |
| F02 |
Hot water temperature sensor fault |
| F03 |
Storage tank temperature sensor fault |
| F10 |
Flow heating temperature sensor fault |
| F11 |
Return heating temperature sensor fault |
| F12 |
Hot water temperature sensor fault |
| F13 |
Storage tank temperature sensor fault |
| F20 |
Overheating fault |
| F22 |
Low water pressure |
| F23 |
Water circulation fault |
| F24 |
Water circulation fault |
| F26 |
Fault in gas valve |
| F27 |
Flame detection fault |
| F28 |
Ignition fault |
| F29 |
Loss of flame during operation |
| F32 |
Incorrect air pressure |
| F49 |
EBUS voltage fault |
| F61 |
Fault in the main board |
| F62 |
Fault in the main board |
| F63 |
Fault in the main board |
| F64 |
Fault in the main board |
| F65 |
Fault in the main board |
| F67 |
Fault in the main board |
| F68 |
Fluctuation of flame signal |
| F70 |
User interface incompatible with the main board |
| F71 |
Flow heating temperature sensor fault |
| F72 |
Permanent temperature difference between flow and return heating sensors |
| F73 |
Heating circuit pressure sensor fault |
| F74 |
Heating circuit pressure sensor fault |
| F76 |
Thermal fuse fault |
| F77 |
Fault in gas valve motor |
| F79 |
Storage tank temperature sensor fault |
| F81 |
Overheating of hot water circuit |
| F83 |
No water in the installation |
| F84 |
Permanent temperature difference between flow and return heating sensors |
| F85 |
Flow and Return heating sensor fault |
| F86 |
Underfloor heating contact fault |
| Err |
User interface fault |
Ultracom CXI Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F9 |
Water pressure sensor fault, blocked flow filter or pump fault |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
| No display or Er |
loose connection X51 |
Ultracom CX Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F9 |
Water pressure sensor fault, blocked flow filter or pump fault |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
| No display or Er |
loose connection X51 |
Ultracom HXI Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F9 |
Water pressure sensor fault, blocked flow filter or pump fault |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
| No display or Er |
loose connection X51 |
Ultracom SXI Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F9 |
Water pressure sensor fault, blocked flow filter or pump fault |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
| No display or Er |
loose connection X51 |
Ultrapower SXI Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F3 |
Fan unable to reach ignition speed |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F9 |
Water pressure sensor fault, blocked flow filter or pump fault |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F15 |
E-bus voltage failure |
| F22 |
Low water pressure or ignition temperature rise too slow |
| F25 |
Circulation fault |
| F43 |
Generic error |
| F70 |
Software incompatible |
| F73 |
Unable to see pump activate |
| F77 |
Condensate pump error (optional) |
| No display or Er |
loose connection X51 |
Xtramax HE Range
| Fault Code |
Possible Cause |
| F1 |
Ignition fault |
| F2 |
Fan |
| F3 |
Fan |
| F4 |
Ignition fault |
| F5 |
Overheat Fault |
| F6 |
Central heating flow thermistor |
| F7 |
Domestic hot water thermistor |
| F8 |
Tank thermistor |
| F9 |
Water pressure sensor fault (please contact GW technical department for further information) |
| F10 |
Central return flow thermistor |
| F11 |
Main board connection fault |
| F12 |
User interface connection fault |
| F13 |
PCB memory or sensing fault |
| F14 |
Gas valve control defective |
| F16 |
Flame detection fault |
| F17 |
Power supply is less than 170v |
| F18 |
User interface fault |
| F19 |
Central heating thermistor unplugged |
| F20 |
Software incompatibility |
| F23 |
Water circulation fault |
| F24 |
Cental heating return temperature > 90 degrees |
| F25 |
Maximum temperature rise slope |
| F26 |
Maximum delta temperature |
Xtrafast 96/120 Range
| Fault Code |
Possible Cause |
| F00 |
No-fault |
| F02 |
Air flow fault |
| F04 |
Ignition fault – flame detection |
| F05 |
Overheating |
| F06 |
Central heating thermistor/wiring fault |
| F07 |
Domestic hot water thermistor/wiring fault |
| F08 |
Storage vessel thermistor/wiring fault |
| F09 |
System pressure sensor fault |
| F10 |
Fan fault |
| F11 |
Poor circulation |
| F12 |
User interface fault |
| F13 |
Main pcb fault |
| F14 |
Central heating flow temperature > 97 degrees |
| F15 |
Gas mechanism fault |
| F20 |
Communication fault |
Xtrafast 96/120E1 Range
| Fault Code |
Possible Cause |
| F00 |
No fault |
| F02 |
Air flow fault |
| F04 |
Ignition fault – flame detection |
| F05 |
Overheating |
| F06 |
Central heating thermistor/wiring fault |
| F07 |
Domestic hot water thermistor/wiring fault |
| F08 |
Storage vessel thermistor/wiring fault |
| F09 |
System pressure sensor fault |
| F10 |
Fan fault |
| F11 |
Poor circulation |
| F12 |
User interface fault |
| F13 |
Main pcb fault |
| F14 |
Central heating flow temperature > 97 degrees |
| F15 |
Gas mechanism fault |
| F20 |
Communication fault |
FAQs
What is the f5 fault code Glow-worm boiler?
The Glow-worm boiler fault code f5 occurs when your boiler enters overheat status, it could be due to previous work, such as airlocks in your central heating system. To prevent the boiler from tripping out, ensure sure there is no air in the central heating system.
What does the f1 error code on a Glow-worm boiler mean?
If the F1 fault code appears on your Glow-worm boiler, it signifies there was a problem with the ignition sequence. There are a number of ignition problems that might cause your boiler to cease working.
Fault codes on Glow-worm boilers will assist your engineer in determining the source of the problem faster than if they were to start from zero. When a fault code appears on the display panel, your boiler will most likely lockout. It won’t operate again until your boiler repair firm has identified the issue.
What is the f22 fault code Glow-worm boiler?
Low pressure is indicated by the F22 boiler trouble code. There’s a strong probability you have a leak if this just appeared on the screen and your boiler is dropping pressure. Otherwise, the system is likely to have an airlock.
What is the f3 fault code on Glow-worm boiler?
Fan unable to attain ignition speed’ is an F3 code on a Glow-worm Boiler. If your Glow-worm Boiler is giving you the F3 signal, it’s possible that the fan is functioning but not at full speed. This can happen if the boiler’s mechanical side is malfunctioning or if a temperamental loose wire is present.
What is Glow-worm boiler f4 fault code?
A small blockage caused the F4 fault codes, which were quickly and easily resolved. There was also no need to get a Gas Safe registered professional to solve the problem because it was not related to the gas boiler.
How do I reset my Glow-worm boiler?
Fault codes beginning with the letter F are shown on glow-worm boilers to indicate defects. Simply push the reset button and wait 5 seconds to restart a Glow-worm boiler. You should be able to observe your boiler come back to life.
What does F75 mean on a Glow-worm boiler?
The F75 code indicates that the boiler failed to perceive a rise in system pressure when it tried to spin the pump during its start-up checks.
