Worcester Bosch Cartridge (3-Way Valve) 87186445620

This is the three-way valve cartridge for Worcester Bosch appliances, supplied under part number 87186445620. The cartridge sits inside the three-way valve assembly and directs water between the heating circuit and the domestic hot water circuit under the control of the diverter actuator. It is a serviceable internal component of the combi boiler's diverter valve rather than the complete valve body.

• Domestic hot water runs hot and cold intermittently, or only heats when a tap is run slowly.
• Radiators warm up when there is a hot water demand, or hot water is drawn when the heating is calling.
• The diverter actuator operates but the valve does not change over between heating and hot water.
• Water weeping from the valve spindle area or around the cartridge housing.
• The valve body feels stiff or the cartridge will not travel freely when moved.

• Confirm the appliance model and GC number against the fit list above, as the cartridge is model-specific.
• Check whether the fault lies with the actuator head or the cartridge itself before replacing, since the two are separate components.
• Inspect the valve body bore and seals for scoring or debris, as a worn body will damage a new cartridge.
• Have the appliance isolated and drained as required before opening the valve assembly.