Source-backed catalogue
Verified boiler fault-code guides
Choose a supported model and code to read the catalogue entry and its source documents.
Glow-worm · Ultracom2 cxi 24/30/35
- Glow-worm F65Excessive main board temperature.
- Glow-worm F83No water in the installation: the temperature does not increase when the burner is lit.
- Glow-worm F84Permanent temperature difference between flow and return heating sensors (inverted, disconnected or defective sensors).
- Glow-worm F85Flow and return heating sensors fault (both sensors connected to the same pipe).
- Glow-worm F86Underfloor heating contact fault.
- Glow-worm F00Flow heating temperature sensor fault (open circuit).
- Glow-worm F01Return heating temperature sensor fault (disconnected).
- Glow-worm F10Flow heating temperature sensor fault (short-circuit).
- Glow-worm F11Return heating temperature sensor fault (short-circuit).
- Glow-worm F20Overheating fault — safety device activated (97°C).
- Glow-worm F23Max temperature difference return/flow — water circulation fault.
- Glow-worm F24Water circulation fault — pump malfunction (rapid temp rise).
- Glow-worm F49EBUS voltage fault (EBUS line / connector short).
- Glow-worm F63Fault in the main board memory.
- Glow-worm F64Fault in the main board — rapid flow/return sensor fluctuation.
- Glow-worm F71Flow heating temperature sensor fault (unclipped/defective).
- Glow-worm F72Permanent temperature difference between flow and return sensors.
- Glow-worm F73Heating circuit pressure sensor fault (shorted/disconnected).
- Glow-worm F74Heating circuit pressure sensor fault.
- Glow-worm F76Thermal fuse fault (disconnected or defective).
- Glow-worm F22F22 indicates low water pressure in the installation.
- Glow-worm F28F28 indicates an ignition fault.
- Glow-worm F29F29 indicates loss of flame during operation.
Checking verified manufacturer coverage…