The Worcester Bosch 87483004840 Junior Printed Circuit Board (PCB) is a genuine replacement control board engineered to manage and coordinate the key electrical functions of your boiler. As the central processing unit of the appliance, this PCB regulates ignition, burner sequencing, pump operation, fan control and safety monitoring to ensure smooth, efficient and reliable heating performance. Built to Worcester Bosch’s exacting specifications, it provides robust performance and long service life under typical domestic heating conditions.

Designed specifically for Worcester Bosch Junior series boilers, the 87483004840 PCB is compatible with models such as the Greenstar Junior and Greenstar Junior II, as well as other variants within the Junior range that reference this part number. This makes it an ideal choice for professional engineers and installers carrying out repairs or maintenance on these compact, wall-hung gas boilers. Before fitting, verify the existing part number on the boiler’s original PCB to ensure you’re replacing with the correct unit.

The Junior Printed Circuit Board is supplied ready to install and integrates seamlessly with existing wiring looms, sensors and actuators in the boiler. Its programmed logic and safety protocols help maintain efficient combustion, protect against fault conditions and support accurate diagnostics. Choosing the Worcester Bosch 87483004840 PCB restores control system integrity, helping your Junior boiler operate reliably and efficiently.