Worcester Bosch Wiring Harness Main 87161217750

The Worcester Bosch 87161217750 is the main wiring harness used across a small group of Worcester Bosch and British Gas badged boilers. It is the primary electrical loom inside the appliance, carrying power and signal connections between the control board and the boiler's fans, sensors, gas valve and other components through a set of moulded plug connectors.

Because the harness sits close to hot surfaces and moving parts, its insulation and connector terminals can degrade over years of service. Replacing the complete loom restores a reliable electrical path where individual wires have become brittle, chafed or intermittent.

• The boiler fails to fire, locks out or shuts down intermittently with no obvious mechanical cause.
• Fault codes appear that point to lost communication or missing signals from sensors and switches.
• The loom shows visible chafing, scorch marks, cracked insulation or exposed conductor.
• Plug connectors are loose, corroded or show signs of arcing or heat discolouration.
• Components such as the fan or pump run correctly when the harness is moved or the connectors are reseated.

• Check the GC number on the appliance data badge against the models listed above before ordering.
• Confirm the number printed on the existing harness, as this part replaces 8-716-105-779-0, 87161057790 and Z/BYK87161217750.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.