Hot water cylinder: repair or replace, honestly

When a hot water cylinder fails, the instinct is either to throw money at a repair or to replace the whole thing. The right answer depends on three things: the age of the unit, the specific fault, and what a new one would cost you to run.

A cylinder under about eight years old with a failed element or thermostat is almost always worth repairing -- the parts are cheap and the tank is sound. Past twelve years, or with a leaking tank, replacement usually wins because the next failure is not far away.

The piece people forget is running cost. A modern heat-pump or well-sized cylinder can pay back its price difference over a few years. We will give you the honest numbers, not just the bigger invoice.