The Draper Immersion Heater Wrench is a heavy duty box wrench designed for the installation and removal of electric immersion heaters in domestic hot water cylinders. This specialist plumbers tool features an integrated tommy bar for additional leverage when working with stubborn or over-tightened heater elements. Sized at 3 3/8" AF (85mm octagonal), this wrench is specifically engineered to fit standard immersion heater nuts found on hot water cylinders with moulded insulation. The box wrench design provides secure engagement around all six faces of the heater nut, minimising the risk of rounding corners during removal or installation. Ideal for plumbers and heating engineers working on domestic hot water systems, this tool is particularly useful when replacing failed immersion heaters or servicing existing installations. The tommy bar allows you to apply controlled torque without requiring additional tools, making it an essential addition to any plumbing toolkit. Features and Benefit