Geyser tripping the MCB: the four usual causes

A breaker tripping is the wiring protecting you. Resetting it repeatedly without finding out why is how a small fault becomes a fire or a shock. Here is what the timing tells you.

Trips instantly, every time

A dead short — most often a heating element whose sheath has cracked and is touching the tank, or water that has reached the thermostat terminals. Do not reset it again. This is a technician visit with the power isolated.

Trips after a few minutes

The element is drawing more current as it heats, and the circuit cannot carry it. Either the element is failing, or the geyser was installed on a circuit rated below its needs. Check the geyser's rating plate against the breaker.

Trips when another appliance runs

Overload, not a geyser fault. The geyser plus the iron plus the microwave exceeds the circuit. The fix is a dedicated circuit for the geyser, which is how it should have been installed.

Trips only the earth-leakage breaker

Current is leaking to earth — a scaled element with a hairline crack, or damp in the housing. This is the one that protects against shock, and it is telling you insulation is failing.

If the geyser trips the earth-leakage breaker and you get even a faint tingle from a tap, stop using the geyser and the tap, isolate the geyser at the MCB, and call. Do not touch the geyser body.

What the repair is

Usually the element; sometimes the thermostat; occasionally the wiring to the unit. All are done with the supply off and the tank drained where needed. None of it is a homeowner job.