Worcester Bosch Burner Nozzle 5.7 8716117683

This is a Worcester Bosch burner nozzle with a 5.7 designation, supplied under part number 8716117683. It forms part of the burner assembly on Worcester Bosch Greenstar ErP Compact gas boilers, where it meters and shapes the gas flow into the combustion chamber so the mixture burns cleanly and at a stable rate. Nozzles are a wear item on the burner circuit and are replaced when combustion readings drift or the flame becomes unstable.

• Combustion analyser readings outside the expected range for the appliance, particularly rising CO with falling CO2
• Sooting or blackening around the burner and heat exchanger surfaces
• A yellow, lazy or lifting flame instead of a steady blue flame
• Repeated ignition faults, flame instability or lockouts traced to the burner circuit
• Rough running or noise from the burner area that does not clear after servicing

• Check the appliance GC number and model plate against the compatibility list before ordering, as several Greenstar ErP Compact variants use different burner components.
• Confirm the part number on the existing nozzle or in the appliance documentation matches 8716117683 or the alternative number 1031023.
• Inspect the burner seals and gaskets while the burner is open and replace any that are compressed, cracked or heat-damaged.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.