Worcester Bosch Code Plug NG 8716121825

The code plug is a small plug-in module used on Worcester Bosch gas boilers to set the appliance identity and fuel type on the control board. This example is the NG (natural gas) version, part number 8716121825, and carries the works reference 20172. It is a Worcester Bosch component intended for the Greenstar 4000 System and GR4700iW 12 S NG System range, where it allows the PCB to recognise the correct appliance variant and gas category.

• The boiler will not run correctly after a printed circuit board change, with the appliance failing to identify its model or fuel type.
• Repeated lockouts or fault codes during start-up that trace back to incorrect appliance configuration rather than a gas or ignition fault.
• The plug is missing, loose in its socket, or shows heat damage, corroded pins or a cracked body.
• A boiler that has been converted or re-commissioned and no longer matches the fuel type or appliance variant recorded on the data plate.

• Check the model and GC number on the appliance data plate against the compatibility list before ordering; the two listed GR4700iW 12 S NG system variants both take this code plug.
• Note the alternative number 8923011 when cross-referencing older documentation or an existing plug.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.