Your boiler has stopped working because it cannot communicate with the internal motor that clears out exhaust gases.

No signal from fan

What causes this fault?

This fault occurs when the boiler's control board cannot detect any movement from the internal fan, which is essential for clearing dangerous exhaust fumes. The most common reason is a mechanical failure within the fan motor or a communication break in the electrical wiring connecting the fan to the main computer. In some cases, the fan may be physically blocked by debris or the control board itself may have stopped sending power to the component.