Overflowing Geyser - Your Essential Guide

25 November, 2019 - Geyser repair & installations

Overflowing Geyser

Is your geyser overflow dripping or pouring? Learn the difference between a normal pressure release and a dangerous warning sign that requires immediate attention

⚠️ EMERGENCY CHECK: If water is streaming out continuously, your valve may have failed. This can lead to dangerous overheating. Do not wait. Call Alpha Plumbing on 010 001 8364 – we are available 24/7 in JHB and PTA and never charge extra after hours.

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What to Do When Your Geyser Is Overflowing?

We’ve all heard the horror stories of burst geysers and the resulting massive water damage they cause to family homes. That risk alone is enough reason for South African homeowners to keep a close eye on their plumbing. It is always cheaper to maintain your system than to deal with a burst geyser, right?

However, if you are already facing an overflowing geyser and are worried about water damage to your property, it is not too late to minimise the impact. We have put together a helpful guide on Damage Controlwith immediate steps you can take to protect your home.

Now, a common thing with geysers is water dripping from the overflow pipe. Why does this happen? Is it normal? And when should you start being concerned?

Intermittent Drip

Normal, as the geyser heats up and cools down (expansion relief)

Continuous or Steady Drip

Needs inspection

Streaming Water

Not normal—call now

Hot Water or Steam

Switch off the geyser immediately and call now

Not Sure? Text a plumber

When is an overflowing geyser a problem

1. The Pressure-Control Valve Might Be Faulty

A steady leak or drip often indicates that the pressure valve or float valve must be replaced or serviced. A professional plumber should be able to replace the valve in no time, depending on how accessible your geyser is.

💡 Tip: If the water overflow is too bothersome or causing problems, switch off your geyser at the main distribution board first and only then turn off the water supply to the geyser.
🔎 Learn More: See our Geyser Repair Services

2. The Thermostat or Temperature Safety Valve Might Be Faulty (Dangerous)

This is more urgent. If the geyser is overheating, the overflow/discharge won’t “drip” anymore—it can shift into a continuous flow or strong stream of very hot water, sometimes with steam coming off the outlet. You might hear hissing sounds or notice abnormally hot water when you open a tap in the house. That’s your warning sign that the thermostat may be stuck “on” or the temperature safety valve is dumping hot water to prevent a dangerous pressure/temperature build-up leading up to the geyser bursting.

⚠️ Warning Sign: A clear sign of the geyser overheating is hot water or steam escaping from the overflow.

🛑 What to do immediately (safe steps):

Switch OFF the geyser using the switch on the main distribution board
Run a hot tap for a few minutes to help reduce temperature/pressure.
Keep people away from the overflow discharge point (scald risk).
Call a qualified plumber – (If you need help now, call 010 001 8364 for 24/7 geyser assistance across Gauteng.)

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Compliance or installation issues that cause ongoing discharge

A geyser installation must be set up so safety components can do their job correctly (and visibly). The Institute of Plumbing of South Africa (IOPSA) stresses the importance of a geyser being installed according to the SANS10254 regulations. If your overflow line disappears into a wall/ceiling or doesn’t discharge visibly, you can have a serious problem without noticing it early.

That is why it is essential to use a qualified plumber who should issue a PIRB plumbing Certificate of Compliance

A simple "litres test" you can do today

Put a bucket under the overflow discharge for 30 minutes after a normal heating cycle.

A few drips: Usually fine.
A measurable amount (cups/litres): investigate
Constant flow: Call a plumber

Also: a hot water leak wastes both water and electricity—Eskom notes even a slow hot water leak costs you twice (water + heating).

How we can help - 24-hours without after-hour fees

Alpha Plumbing offers 24-hour plumbing support. And, because we know emergencies happen, we do not charge extra after-hours rates when you’re dealing with a crisis. We offer 24-hour geyser repair and installation services across Gauteng and you can call us on 010 001 8364

24-Hour Helpline

👉 Read our step-by-step guide on minimizing damage from a faulty geyser while you wait for us.