Glow Worm Boiler Fault Finding Codes

• 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
• F9 – Low Water Pressure Sensor
• F10 – Central Return Flow Thermistor
• F11 – Flow or Return Thermistor Fault
• F12 – Connection fault between main PCB and display PCB
• F13 – PCB memory or sensing fault
• F14 – Gas Valve Control Defective
• F15 – E-Bus Voltage Failure
• F16 – flame detection fault
• F17 – Power supply is less than 170v
• F18 – User interface fault
• F19 – Central Heating Thermistor Unplugged
• F20 – Software Incompatibility
• F22 – Low Water Pressure or ignition temperature rise too slow
• F24 – Central heating return temperature
• F25 – Circulation Fault
• F26 – Poor Circulation
• F43 – Generic Error
• F70 – Software Incompatible
• F73 Unable to see pump active
• F77 Condensate Pump Error (optional)
• No display or ER – Loose connection X51