A Printed Circuit Boards (PCBs) is the brains of a modern boiler. It processes multiple inputs and regulate many valves, sensors etc. to provide efficient heating and hot water. PCBs are precision electrical devices, carrying delicate circuitry for monitoring and control, whilst also carrying high voltages for operating heavy current devices such as fans and pumps. They operate in the challenging environment of the boiler case with extremes of heat, water and vibration. When a PCB fails it is often uneconomic to repair, so a replacement is the preferred option.