If you’ve spotted water dripping or running from the small pipe sticking out of a wall or from under your geyser, that’s the overflow pipe, and it’s one of the most common geyser problems we’re called out for across Cape Town. Here’s what causes it, whether it’s something to worry about, and what a proper repair involves.
What Is the Geyser Overflow Pipe For?
Every geyser installation includes a pressure relief valve (also called a PRV or safety valve) connected to an overflow pipe that runs outside, usually terminating near ground level or through an external wall. Its job is to release excess pressure or temperature from the tank before it can build up to a dangerous level. In other words, a small amount of dripping is the valve doing exactly what it’s designed to do. Continuous leaking or a steady trickle, on the other hand, is a sign that something needs attention.
Common Causes of an Overflow Pipe Leak
1. High Municipal Water Pressure
Water pressure varies significantly across Cape Town, and homes in areas with higher supply pressure, such as parts of the Southern Suburbs, City Bowl and Atlantic Seaboard, place extra strain on a geyser’s pressure relief valve. Without a pressure-reducing valve fitted on the incoming line, the PRV can end up doing far more work than it should, and start to leak as a result.
2. A Worn or Faulty Pressure Relief Valve
Like any mechanical part, the PRV wears out over time. Mineral deposits and scale, common in areas with harder water, can stop the valve from sealing properly once it has released pressure, leaving it dripping continuously even under normal conditions.
3. Thermal Expansion
As water heats up it expands. In a closed water system without an expansion vessel, that extra volume has nowhere to go except out through the overflow pipe. This is especially common in newer installations with non-return or pressure-control valves fitted at the meter.
4. Thermostat Set Too High or Faulty
If a geyser’s thermostat is set too high, or has failed and is overheating the water, the pressure inside the tank rises well beyond normal levels, forcing the safety valve to release more often than it should.
5. An Ageing or Failing Geyser
Older geysers, particularly those that haven’t been serviced in several years, are far more prone to pressure problems as scale builds up inside the tank and components start to wear.
Is It Safe to Leave It Dripping?
An occasional drip, especially after hot water has just been used, is generally nothing to worry about. A steady leak or a constant flow is not something to ignore. Left unaddressed, it wastes water, can point to dangerously high pressure or temperature inside the tank, and may lead to a much more serious geyser failure or burst if the underlying cause isn’t fixed.
How We Diagnose and Fix It
When we attend a leaking overflow pipe anywhere in Cape Town, we start by testing your municipal water pressure and the geyser’s temperature and pressure settings. Depending on what we find, the fix may involve replacing a worn pressure relief valve, fitting a pressure-reducing valve or expansion vessel, correcting the thermostat setting, or, in some cases, a full geyser inspection if the tank itself is at the end of its life. Every repair is completed by qualified, insured plumbers, with a Certificate of Compliance issued where required.
Leaking Geyser Overflow Pipe in Cape Town? We Can Help
Whether you’re in the Southern Suburbs, City Bowl, Atlantic Seaboard, Northern Suburbs or anywhere else across Cape Town, our team diagnoses and repairs leaking geyser overflow pipes quickly, and can advise on the right long-term fix so it doesn’t keep happening. Call us on 021 203 5337 or request a free quote online and we’ll get it sorted. You can also read more about our geyser repair services or check the areas we service across Cape Town.