Worcester Bosch Pump Head Standard 15/50 87161135930

The Worcester Bosch 87161135930 is a standard 15/50 pump head supplied by Worcester Bosch. It forms the motor and impeller section of the circulating pump, driving heating water around the boiler's primary circuit and out to the radiators and hot water cylinder. The pump head is the replaceable working half of the pump assembly, so it can be renewed without disturbing the pump body or the pipework connections.

• The boiler fires but the radiators stay cold while the flow and return pipes at the boiler heat up normally
• The pump runs noisily, with grinding, humming or rattling from the pump housing
• The pump head is hot to the touch but the spindle is not turning, or the impeller can be felt to be stiff or seized
• The boiler locks out or trips on overheat because circulation has stopped
• Kettling or banging from the heat exchanger as localised boiling occurs with poor water movement

• Confirm the part number on the existing pump head matches 87161135930 before ordering
• Check the boiler's serial plate and model details so the correct pump variant is selected
• Inspect the pump gasket or O-ring seal at the same time, as the seal is normally disturbed when the head is removed
• Isolate the electrical supply and drain or isolate the pump section before dismantling