Worcester Bosch Venturi Assembly 31kW 8737708865

The venturi assembly is the air gas mixer fitted to Worcester Bosch 31kW Greenstar 8000 Life boilers. It sits in the combustion air path and draws gas into the air stream at a controlled rate, so the burner receives a correctly proportioned mixture. Over time the internal profile and sealing faces can wear or become contaminated, which upsets combustion and shows up in flue gas readings.

• Combustion readings outside the expected range for the appliance, with CO or CO2 drifting from the commissioning figures
• Unstable or lifting flame at the burner, or a flame picture that will not settle after servicing
• Sooting or discolouration around the burner and heat exchanger area
• Rough running, popping or unusual noise on ignition or during firing
• Repeated lockouts or ignition faults that persist after the usual service checks

• Check the GC number and appliance serial plate against the compatibility list to confirm the boiler is a 31kW Greenstar 8000 Life variant covered here
• Confirm the part number on the existing venturi matches 8737708865 or the alternative number 2249308 before ordering
• Inspect the burner and combustion seals while the appliance is open, as disturbed gaskets and seals may need renewing at the same time
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.