| E151 | Internal error of the boiler's PCB. | Internal fault of the PCB. Check voltages/grounds and connectors; if the error persists after reset and checks, confirm by replacing the PCB. |
| E154 | Internal boiler PCB error. | Internal fault of the PCB. After reset and wiring inspection, if it reappears, check the power supply and replace the PCB. |
| E135 | Internal fault of the card. | Internal fault of the PCB. Check power supply and perform a reset; if it does not resolve and there are no other causes, replace the board. |
| E.02 .16 | Timeout communication with the internal memory of the boiler's control board. | The PCB cannot communicate with its internal memory (board fault). Check for electromagnetic disturbances and connections; if the issue persists, replace the main board. |
| E.02 .17 | Permanent communication failure between the gas valve and the boiler PCB. | Communication fault of the PCB (bus/control) with the gas valve due to a fault in the board or line. Check harness/connectors CN1/CN2 and EMI; if not resolved, replace the board. |
| H.01 .00 | Temporary communication failure between the gas valve and the boiler PCB. | Temporary communication interruption managed by the PCB; when the board fails, the warning reappears. Check CN1/CN2 and supply; if it persists, replace the main board. |
