Worcester Bosch Flame Sensing Electrode Highflow 400 87161045110

The Worcester Bosch 87161045110 is a flame sensing electrode for the Highflow 400 Electronic range of floor-standing gas appliances. Mounted in the burner assembly, it sits in the flame path and returns an ionisation signal to the control board while the burner is lit. If that signal is lost, the board shuts the gas valve and the appliance goes to lockout.

• The appliance fires, then locks out within a few seconds of the burner lighting.
• Repeated lockouts that clear on reset but return on the next demand for heat or hot water.
• The burner lights and the flame is visibly established, but the board does not register it and shuts the gas valve.
• The ignition sequence runs to the end of its trial period without the board confirming flame.
• Intermittent lockouts that become more frequent as the electrode degrades.

• Check the GC number on the appliance data badge against the list above; the Highflow 400 Electronic variants use different GC numbers for each gas and flue configuration.
• Confirm the previous part number 501165 against the electrode removed from the appliance before ordering.
• The part carries the WSE obsolete reference, so confirm availability before booking the job in.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.