Glow Worm Fault Codes

Comprehensive reference table of all Glow Worm boiler error codes. Click any code for detailed troubleshooting steps.

Pro Tip

Check your boiler's digital display panel (usually behind a drop-down cover) to find the current active fault code.

Error CodeDescription
F.22Safety switch-off: Low water pressure in the boiler.
F.28
Fault: Ignition unsuccessful when starting up.
F.29
Fault: Flame loss during operation; possible condensate blockage.
F.75
Fault: Pressure sensor; no pressure jump detected upon pump start.
F.32
Fan frost protection active: Fan speed outside tolerance values.
F.20
Safety switch-off: Overheating temperature reached.
F.23
Safety switch-off: Temperature difference too great between NTC1/NTC2.
F.27
Safety switch-off: Fault in flame detection (false flame).
F.61
Fault: Gas valve control system; short circuit or defective electronics.
F.83
Fault: EEPROM defective electronics or fault with burner temperature sensor.
F.00
Fault: Flow temperature sensor disconnected or defective.
F.01
Fault: Return temperature sensor disconnected or defective.
F.10
Short circuit: Flow temperature sensor.
F.11
Short circuit: Return temperature sensor.
F.24
Safety switch-off: Temperature rises too fast.
F.25
Safety switch-off: Flue gas temperature too high.
F.33
Air pressure switch fault: Pressure monitor has not switched.
F.64
Fault: Electronics/sensor/analogue-to-digital converter.
F.71
Fault: Flow/return temperature sensor.
F.72
Fault: Deviation in the water pressure sensor/return temperature sensor.
F.73
Water pressure sensor not connected or has short-circuited.
F.76 / F.78
The safety cut-out in the primary heat exchanger is defective.

Anything Else?

Get a Free Quote

Instant fixed-price quotes for new boiler installations

Get Instant Quote

Need Something Else?

Speak to our team for expert advice

We use cookies for analytics and to improve your experience. By continuing, you agree to our Cookie Policy.