Worcester Bosch Pressure Relief Valve Greenstar Heatslave 87161104070

This is a pressure relief valve assembly manufactured by Worcester Bosch for the Greenstar Heatslave range of oil-fired boilers. It sits on the heating circuit and opens when system pressure rises beyond the set threshold, discharging water safely rather than allowing stress to build inside the boiler, cylinder or pipework. Once pressure falls back to normal, the valve is designed to close and reseat.

• Water continually discharging from the boiler's pressure relief discharge pipe, even when the system is cold
• System pressure dropping repeatedly and needing regular topping up
• The valve weeping or dripping from the outlet after it has operated
• Scale, sludge or debris preventing the valve from seating properly when it closes
• Boiler locking out or cutting out because system pressure cannot be maintained

• Confirm the model and serial number of the appliance against the compatibility list before ordering, as the Heatslave range covers several internal and external variants
• Check the existing valve on the appliance and match it to part number 87161104070 or the alternative number 1015657
• Inspect the sealing face and any associated washer or gasket on removal, as a worn seal will let the new valve pass water
• This part is not classified as a gas-carrying component, but work inside the appliance casing should still be carried out by a competent person