Your geyser works hard every day, and most homeowners only think about it when the hot water stops. A geyser rarely fails without warning, though. Knowing the signs that it's reaching the end of its life lets you plan a replacement instead of dealing with a burst geyser and a wet ceiling.
Some of these signs point to a repairable fault, such as a thermostat or element. Others mean the cylinder itself is failing. A qualified plumber can tell you which, but here's what to look out for.
1. Water leaking from the geyser itself
A leak from a valve or fitting can often be repaired. A leak from the body of the cylinder usually can't. Once the tank has corroded through, it will only get worse. Look for water in the drip tray, damp patches or brown stains on the ceiling below the geyser, or water running from the overflow pipe more than it should.
Safety first: if water is leaking near the geyser's electrical connection, switch the geyser off at the distribution board before doing anything else, and don't touch wet electrical parts.
2. Rusty or discoloured hot water
If the cold water runs clear but the hot water is brown or rusty, the inside of the geyser may be corroding. Geysers contain a sacrificial anode that protects the tank. Once it is used up, the tank itself starts to rust. Discoloured water can also come from old galvanised pipes, so a plumber should confirm the source.
3. Inconsistent or not enough hot water
Hot water that runs out much faster than it used to, or swings between hot and lukewarm, can mean a faulty element or thermostat. Both can be replaced. It can also mean sediment has built up at the bottom of the tank, reducing its effective capacity. If these faults keep coming back, replacement often makes more sense than repeated repairs.
4. Rumbling, banging or popping noises
A geyser that rumbles or pops as it heats often has sediment build-up. The noise comes from water trapped under the sediment boiling. This makes the element work harder and adds stress to the tank. Loud banging can also be caused by pressure problems elsewhere in the system, which should be checked.
5. The pressure valve keeps discharging
A pressure control valve and a temperature and pressure (T&P) valve protect your geyser. If water regularly runs from the overflow, a valve may be faulty or the pressure in the system may be too high. Don't block or cap an overflow pipe. It's a safety feature. Have a plumber find out why it's discharging.
6. Recurring faults and repairs
If you've replaced the element, the thermostat and a valve within a short period, it's worth asking whether the geyser is worth saving. Each repair costs money, and an ageing cylinder may still fail. A plumber can compare the cost of another repair with the cost of a new geyser. Our guide to plumber costs in Johannesburg explains what affects that price.
7. Age and visible corrosion
Look at the outside of the geyser and its fittings. Rust on the casing, corroded connections or a sagging support suggest the unit is ageing. How long a geyser lasts depends on water quality, pressure and maintenance. If yours is old and showing other signs on this list, it's sensible to start planning a replacement before it fails.
Repair or replace?
As a rule of thumb:
- Usually repairable: faulty thermostat or element, leaking valve or fitting, tripping caused by a single faulty part.
- Usually needs replacing: a leak from the cylinder itself, rusty hot water from a corroded tank, or repeated faults on an old unit.
The only way to know for sure is to have the geyser inspected by a qualified plumber.
What to do if your geyser is leaking or has burst
- Switch the geyser off at the distribution board.
- Close the cold water supply to the geyser using its isolating valve, or close the main water supply to the property.
- Protect your belongings under the leak and, if the ceiling is bulging with water, keep people away from it.
- Take photos for your insurer if you plan to claim.
- Call a plumber. For more steps, see our emergency plumbing guide.
Why geyser work needs a qualified plumber
A geyser combines water under pressure, high temperatures and mains electricity. Installation in South Africa must comply with the relevant national standards, including the correct safety valves, drip tray and overflow. Insurers commonly expect the work to be done by a qualified plumber. DIY geyser work isn't worth the risk to your safety, your property or your insurance cover.
Geyser replacement in Johannesburg
Badge Plumbers handles geyser installation, troubleshooting and repairs for homes and businesses across Johannesburg, including Randburg, Midrand, Fourways and Sandton. You can see examples of our geyser replacements in North Riding and Cresta in our project portfolio. If you've noticed any of these signs, contact us and send a photo of the geyser and its label if you can. It helps us advise you quickly.
