Ao Smith 3 Liter Geyser Heating Element - Heavy Duty, New Model, ISI Standard (Match And Buy)

Mains electricity and a tank of very hot water. If you are not confident with this, a plumber or geyser technician will fit it in under an hour. Never work on a geyser that is still switched on or still full.

1. Switch off and prove it is dead. Turn the geyser off at its own switch and at the MCB in the consumer unit. The geyser switch alone is not enough.
2. Let it cool. A tank that has just heated holds water near boiling. Leave it an hour or more before draining.
3. Close the inlet and drain the tank completely. Shut the inlet valve, open a hot tap to break the vacuum, then open the drain valve and let it empty. Nothing will come out of the flange until the tank is truly empty — and if it is not, it will come out over you.
4. Open the cover and photograph the wiring. Remove the bottom cover plate and take a clear photo of which wire goes to which terminal before anything is disconnected. This is the step that saves the job.
5. Remove the old element. Disconnect the wires, then undo the flange bolts evenly in a cross pattern. Ease the element out — heavy scale may need it worked free gently. Expect sludge.
6. Clean the seat and use the NEW gasket. Wipe the flange face completely clean. Always fit the new gasket supplied; a reused one will weep. Do not add sealant.
7. Tighten evenly. Bolts finger-tight first, then a little at a time in a cross pattern so the gasket seats squarely. Do not overtighten — that distorts the flange and causes the leak it was meant to prevent.
8. Fill the tank BEFORE you switch on. Close the drain, open the inlet, and leave a hot tap running until the flow is steady with no spitting air. Switching on a dry element destroys it in seconds and is not covered by warranty.
9. Check for leaks, then power up. With the tank full and the flange dry, restore power and let it heat one full cycle. Check the flange again once it is hot and the metal has expanded.

If the new element trips the MCB straight away, switch off and call a technician — that points to a wiring fault or a failed thermostat, not a faulty element.