Modern gas boilers have microchip-based adjustment and control systems. They detect malfunctions and display error codes on the screen, which denote faults occurring in the boiler’s units. Boilers’ control systems react differently to faults, depending on the possible consequences:
- Emergency shutoff is activated and blocks the boiler’s work immediately. To clear the error, restart the boiler by pressing the Reset button. Thus you will restore the boiler to factory default settings.
- Emergency shutoff is activated, but the boiler is not blocked. When the error is cleared, the boiler will get back to work with all user settings intact.
- There are warning codes, which do not require immediate interference and do not stop the boiler.
| CODE | CAUSE | ACTION |
|---|---|---|
| AL10 | Ignition failure/not flame sensed, condense sensor activated | Reset, check appliance operation |
| AL20 | Limit thermostat fault, blocked flue switch, flue thermostat | |
| AL21 | External device fault (UHT/CPA) | Reset, check appliance |
| AL26 | Return temperature too high | Reset, check pump, ensure there is sufficient flow sensor temperature). Circulation around heating circuit/s |
| AL28 | Temperature differential inverted (return sensor temperature higher than flowsensor temperature) | Reset, check pump, ensure there is sufficient circulation around heating circuit/s thermistors |
| AL29 | Flue sensor over temperature lock out | Reset check appliance operation |
| AL34 | Fan blower signal fault | Reset check appliance operation, check fan |
| AL40 | Insufficient system water pressure | Check/refill system pressure, reset, check |
| AL41 | Insufficient system water pressure | Check/refill system pressure, check appliance operation |
| AL52 | Internal fault | Reset, check boiler operation |
| AL55 | Jumper tag fault | Check jumper tag configuration |
| AL60 | Jumper tag fault | |
| AL71 | Primary (flow) sensor fault | Check primary thermistor, check wiring |
| AL73 | Return sensor fault | Check return thermistor, check /wiring |
| AL74 | Variation on temperature of primary | Reset, check boiler operation, check and/or return too high pump, ensure there is sufficient circulation around heating circuit/s |
| AL79 | Flow temperature too high, or temperature differential between Drimarv and return too hiqh | Reset, check appliance operation, check thermistors |
| AL91 | The main heat exchanger need to be cleaned | Call the Raypak technical service |