Geyser elements explained: sizes, prices and when yours needs replacing
A geyser element is a low-cost part that quietly decides what your hot water costs you. Here is how to tell when yours is on the way out, what size you need, and what a replacement involves.
1. What a geyser element actually does
The element is the heating coil inside your geyser. Current passes through it, the coil heats up, and the heat moves into the water around it. Everything else in the tank supports that job or keeps it safe: the thermostat switches the element on and off, and the valves manage pressure.
It is also the part doing almost all of the work. A 150 litre geyser on a 3 kW element uses roughly 7 to 9 kWh a day, which is 30 to 50 percent of household electricity consumption in most South African homes, according to the complete electric geyser guide. When the element stops working properly, that consumption does not fall. It usually rises.
2. Geyser element sizes: 2 kW, 3 kW and 4 kW
Element wattage sets how fast the tank heats, not how hot the water gets. That is the thermostat's job. A higher wattage heats the same tank faster and draws more current while it runs, so it has to suit both the tank and the circuit feeding it.
| Element | Typically suits | What it means in practice |
|---|---|---|
| 2 kW geyser element | Smaller tanks, 50 to 100 litres, and point-of-use units | Slower heat-up, lower instantaneous draw. Often used where the electrical supply is limited |
| 3 kW geyser element | 150 litre domestic geysers, the most common size in South African homes | The standard replacement. Heats a 150 litre tank from cold in roughly two to two and a half hours |
| 4 kW geyser element | Larger tanks, 200 to 250 litres, and homes wanting faster recovery | Faster recovery between showers, higher draw while running. Check the breaker and cable rating before fitting one |
Kwikot's standard replacement element is the Kwikheat Standard Spiral Element 3kW (SKU ELK138-KWI). the 3kW element is the standard for a 150l geysers but will fit all sizes of geyser and fits 150 litre electric and solar water heaters. If you are unsure what size tank you have, what size geyser do I need works backwards from household size to capacity.
Back to top ^3. Five signs your geyser element has failed
- No hot water at all. If the geyser has power and the water stays cold, the element or the thermostat has failed.
- Water that is warm but never hot. A partly failed or heavily scaled element still heats, but cannot reach the set temperature.
- Hot water that runs out sooner than it used to, because the tank is recovering too slowly between draws.
- The geyser trips the earth leakage. A cracked element sheath lets current reach the water. Stop using it and call a plumber.
- An electricity bill that climbs with no change in habits. A scaled or failing element runs for longer to reach the same temperature.
That last one is the easiest to miss. If you want a baseline to compare against, the geyser running cost calculator gives you a monthly figure to measure the bill against.
Back to top ^4. Why elements fail
Three causes account for most failures, and two of them are avoidable.
Scale
Dissolved minerals in hard water bake onto the element surface. The coating insulates the element from the water, so it runs hotter and longer to do the same work, and eventually burns out. This is the main reason elements fail early in hard water areas.
A failed thermostat
A thermostat stuck closed leaves the element running continuously. Kwikot names thermostat failure as one of the most common causes of overheating, excessive energy use and premature failure. Replacing an element without checking the thermostat is how people end up doing the job twice.
Age
Elements are consumable. Kwikot recommends replacing the element every five to seven years as part of normal geyser servicing, against a tank lifespan of eight to twelve years with a service every three to four years.
Because the two parts fail together so often, plumbers usually quote them together, which is why "geyser element and thermostat price" is a common search. The matching part is the Kwiktherm clip-on thermostat in the 20 amp range.
Back to top ^5. What a geyser element costs in South Africa
An element is one of the cheapest parts in the geyser and one of the most expensive to ignore. The cost splits three ways: the element, the thermostat if it goes at the same time, and the labour to drain the tank and fit them.
Whatever you pay, buy a genuine part. A cheap element with the wrong sheath material or the wrong length for your tank fails faster and can take the thermostat with it, and the same logic that applies to the risk of second-hand geysers applies to bargain spares. Genuine parts are listed under geyser spares and accessories.
6. How a geyser element is replaced
The job itself is short. Getting to it safely is the part that matters.
- Switch the geyser off at the distribution board, not just at the isolator switch.
- Close the inlet valve and open a hot tap to release pressure.
- Drain the tank through the drain cock. A 150 litre tank takes time and the water is hot.
- Disconnect the wiring, remove the old element and its gasket, and clean the seating face.
- Fit the new element with a new gasket, refit the thermostat in the pocket, and torque evenly.
- Refill the tank completely before switching the power back on. Energising a dry element destroys it in seconds.
- Check for leaks at the flange once the tank is full and under pressure.
That last step is where most DIY attempts come unstuck. A flange that weeps under pressure is not obvious until the ceiling is wet.
Whichever route you take, keep the paperwork. If your geyser is registered, the warranty position is clearer when something goes wrong, which is the argument in register your geyser. If you would rather not do it yourself, log a service call and a technician will handle the drain, the drain cock and the fitting.
Back to top ^7. Solar geyser elements: what is different
A solar geyser still has an electric element. It is the backup for overnight heating and overcast days. 3kW element is the standard for 150l geysers inc solar geysers. What differs is the duty cycle: on a working solar system the element runs far less, so a solar geyser element failing early usually points at a fault on the solar side rather than the element itself. The solar water heating range covers the system side.
8. How to make the next element last longer
- Service the geyser every three to four years. The service is when scale is dealt with and the anode is checked, and both protect the element.
- Set the thermostat to 55 to 60 degrees. Hotter water accelerates scale formation and makes the element work harder for no practical benefit.
- Replace the element and thermostat as a pair. A tired thermostat will shorten the life of a brand new element.
Fit a geyser blanket to cut standing heat loss, so the element cycles less often to hold temperature.
Book the service before winter rather than during it. Winter geyser maintenance covers the seasonal checks, and Kwikot notes that geyser claim volumes climb by around 30 percent in winter.
Back to top ^9. Frequently asked questions
How long does a geyser element last?
Kwikot recommends replacing the element every five to seven years. In hard water areas, or where the thermostat is set high, it can be considerably less. The tank itself lasts eight to twelve years with a service every three to four years.
What size element does a 150 litre geyser take?
A 3 kW element is the standard fit for a 150 litre domestic geyser in South Africa. The Kwikheat Standard Spiral Element 3kW (ELK138-KWI) is specified for 150 litre electric and solar water heaters and has a thermostat pocket.
Can I replace a geyser element myself?
Physically it is a short job, but it involves isolating mains power, draining a tank of near-boiling water and re-sealing a flange that must hold under pressure. A leak at the flange is not obvious until there is ceiling damage. Must be done by plumber or electrician.
Should I replace the thermostat at the same time?
Usually yes. A thermostat stuck closed leaves the element running continuously and is one of the most common causes of premature element failure, so replacing a new element behind an old thermostat often means doing the job twice.
Why does my geyser element keep burning out?
Repeated failures point at something other than the element. The usual causes are scale build-up from hard water, a faulty thermostat, or a non-genuine element of the wrong specification for the tank. A service that addresses scale and checks the thermostat is the fix, not another element.
Does a solar geyser have an element?
Yes. The electric element is the backup for overcast days and overnight heating. On a working solar system it runs far less than on an electric-only geyser, so early failure usually indicates a fault elsewhere in the system.
More on warranties, servicing and spares is in the consumer FAQs.
Back to top ^Always consult a qualified installer and confirm exact product specifications with a Kwikot dealer before purchasing. Information in this guide is for general reference and is subject to change. Contact Kwikot for support.