Error, fault and alarm codes of products - what each code means, its causes and what to do - read from the manufacturers’ manuals, with the manual page each answer comes from.
The flue thermostat has sensed high flue gas temperature (110°C) and reduced burner output to prevent damage. The manual's first action is: “Air in heat exchanger Restricted primary flow Heat exchanger air flow blocke…
The system has detected a break in the external sensor circuit. The manual's first action is: “Check external sensor and cable are not damaged or wet Check continuity of external sensor and circuit connecting block”
The boiler has attempted to fire repeatedly for the maximum time limit. The manual's first action is: “Check external control (room thermostat) requests Rapid on/off hot tap requests”
The system has lost its ability to confirm the flame is burning properly. The manual's first action is: “Check gas supply/working pressure Check flame sensing electrode and lead Check for flue gas recirculation Check/…
The system lost its flame signal after a fan purge attempt. The manual's first action is: “Check flame sensing electrode and lead Check for flue gas recirculation Check/adjust the gas valve settings Check/adjust the f…
The boiler cannot operate due to insufficient supply voltage. The manual's first action is: “Check mains power supply”
Loss of communication with external control (Alpha Climatic) The manual's first action is: “Remote control or receiver connection wiring Remote control or receiver”
Flue sensor fault indicates the flue sensor resistance is out of range. The manual's first action is: “Check sensor wiring connection Flue sensor faulty”
The system is detecting insufficient primary flow due to rapid temperature rise in the primary sensor. The manual's first action is: “Blocked or restricted primary flow Air in heat exchanger Boiler or heating circuit …
The system has overheated and is locked out to prevent damage. The manual's first action is: “Air in heat exchanger Blocked or restricted primary flow Heat exchanger air flow blocked Flue restriction Flue sensor fault…
Control panel button fault code 24 indicates a stuck button or jammed PCB buttons. The manual's first action is: “Check for jammed control panel buttons”
The flame sensing fault code 20 indicates a problem with detecting the flame or failing to open the gas valve after detection. The manual's first action is: “Check flame sensing electrode and lead PCB fault”
The fan has malfunctioned or the PCB is faulty. The manual lists no action for this code.
Error code 15 indicates an internal wiring error in the system. The manual lists no action for this code.
The cylinder sensor has failed or its wiring connections are loose. The manual lists no action for this code.