Worcester Bosch Air Pressure Switch 87161048960

The Worcester Bosch air pressure switch is a safety device fitted to a range of Worcester gas boilers. It monitors the pressure created by the combustion fan and confirms that air is being moved through the appliance before the burner is allowed to light. The printed circuit board reads the switch during the start-up sequence, so the boiler will not fire if the fan is not running correctly or the flue path is restricted.

By proving fan operation, the switch prevents the appliance from running without a means of clearing combustion products. It is a serviceable component and is replaced as a complete unit.

• The boiler attempts to start but locks out before the burner ignites
• The fan runs but the appliance does not prove air pressure and will not fire
• Repeated lockouts or fault codes relating to fan or air pressure on the PCB
• Intermittent ignition, with the boiler sometimes starting and sometimes failing
• The fan runs continuously or the appliance shuts down shortly after start-up

• Check the GC number on the appliance data badge against the compatibility list to confirm the correct variant
• Confirm the model and serial number, as several SI II and RD variants use different switch settings
• Cross-reference the alternative part numbers below if the original label is missing or unreadable
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.