Your boiler's computer system is having trouble completing a reset or start-up sequence and needs a technician to check it.

Reset error.

What causes this fault?

This fault happens when the boiler's internal computer fails to properly complete its reset process or becomes stuck during a startup sequence. It is often caused by a communication failure between the electronic control board and the internal wiring, or a hardware defect within the board itself. Because the boiler can no longer verify its safety checks, it stops running to prevent any erratic behavior.