Why Is My Geyser Not Heating Water?
A geyser that has stopped heating water is one of the most common calls we get in Cape Town, and the cause can range from a simple switch that has tripped to a part that needs replacing. Before you call a plumber, here are the most likely reasons your geyser has gone cold, and which of them are safe to check yourself.
1. The Isolator Switch or Circuit Breaker Has Tripped
Every electric geyser is wired through its own isolator switch, usually mounted on the wall near the geyser or in the ceiling, as well as a dedicated circuit breaker in your distribution board. Check that the isolator switch is in the “on” position and that the breaker in your DB board hasn’t flipped. If it trips again as soon as you reset it, stop and call a professional — this usually points to a fault in the element or wiring rather than a simple overload.
2. A Faulty Thermostat
The thermostat controls when the element switches on to heat the water. If it fails, the element may never receive the signal to heat, even though the geyser has power. This is not a DIY repair, since it involves working inside a pressurised, wired cylinder.
3. A Burnt-Out Heating Element
The element is the part that actually heats the water, and like any heating element it wears out over time, especially in areas with harder water where scale builds up on its surface. A burnt-out element is one of the most common reasons for a geyser that runs cold, and it’s a straightforward, affordable repair for a qualified plumber.
4. Sediment and Scale Buildup
Over several years, sediment settles at the bottom of the tank and scale builds up on the element. This makes the geyser work harder, heat less efficiently, and in some cases stop heating properly altogether. Regular geyser maintenance and the occasional flush can add years to a geyser’s working life.
5. Gas Supply Issues (Gas Geysers)
If you have a gas geyser, a cold water supply can often be traced back to the gas side rather than the water side: a pilot light that has gone out, a closed or faulty gas valve, or an empty gas bottle. Gas appliances should only ever be inspected and repaired by a registered gas practitioner.
When to Call a Professional
Any fault involving electrics, gas, or a pressurised cylinder carries real risk, and a wrong DIY fix can turn a repair into a much bigger and more expensive problem. If resetting the isolator switch or circuit breaker doesn’t solve it, it’s time to bring in a qualified plumber.
Need Your Geyser Looked At?
Our team diagnoses and repairs electric and gas geysers across Cape Town, from a simple element replacement to a full geyser installation with Certificate of Compliance. Call us on 021 203 5337 or request a quote online and we’ll get your hot water running again.
Need a professional to look at your geyser? See our plumbing services in Cape Town.