Worcester Bosch C6 Fault Code

What causes the Worcester Bosch C6 fault?

This fault occurs when the boiler's internal computer detects that the fan is spinning at a higher speed than required for safe combustion. Often, this is caused by a communication error between the main control board and the fan, or a physical blockage in the flue that disrupts the internal air pressure. Over time, electrical components within the fan motor can also wear out, leading to unpredictable speeds that trigger an automatic shutdown.