A homeowner up on the ridge in Northcliff called us after his geyser tripped for the third time in just over a year. He had already replaced the whole unit twice. He was ready to blame the geyser brand, the electrician, anything. When we pulled the element, it was crusted white, three millimetres of calcium scale caked onto the heating coil. The element was running hot because the scale was insulating it from the water. That is what was burning it out.
We tested the cold feed at the meter. Hardness came back at around 180 mg/L, well into the moderately-to-hard range for municipal water on the Randburg ridge. Every time the geyser heated up, calcium was dropping out of solution and welding itself to the element, the tank walls, and the inlet elbow.
We fitted a 32-litre ion-exchange softener in the garage, just after the water main, before the split to the geyser. A fresh element went into the geyser at the same time. Twelve months later, we pulled the element again on his annual service. Clean as new. No scale. He has not called about a tripped geyser since.
Hard water is a silent tax on every fitting in your house. If you want to see what the full water filtration and water purification options look like, we cover the whole picture.