A leaking hot water cylinder can often be repaired if the leak is coming from a pipe connection or valve. If the cylinder body itself is leaking or corroded, replacement is usually the more sensible option. The answer depends on where the water is coming from and the overall condition of the cylinder.
Leaks That Are Often Repairable
Many leaks around a cylinder come from the fittings rather than the cylinder. A compression joint that has worked loose, a worn olive or a weeping fitting can often be tightened, remade or replaced. These are usually small repairs.
Valves are another common source. A drain valve or gate valve that drips may need new packing, a new washer or a full replacement. Short sections of nearby pipework can also be repaired or renewed if they are damaged.
In these cases, the cylinder itself is still sound. Once the faulty part is fixed, it can usually carry on working as before.
Leaks That Usually Mean Replacement
If the leak is coming from the body of the cylinder, a lasting repair is unlikely. Cylinders can corrode from the inside over many years, and once the metal is thin or has a pinhole, patching it is rarely reliable.
Signs that may point to a body leak include water collecting at the base with no clear source above, green or blue staining on the copper, or dampness under the insulation jacket. These signs can have other causes, though, so it is worth having the cylinder checked before deciding.
Leaks near the immersion heater boss can be harder to judge. Sometimes a seal is the problem, but corrosion around the boss can also be the cause. As there are electrics nearby, keep clear of any wet area and leave electrical parts to a qualified electrician.
Deciding Whether a Repair Is Worth It
Whether a repair makes sense depends on more than the leak itself. The age of the cylinder, its general condition, how well it heats water and whether it still suits your household all play a part. If an older cylinder has a small fitting leak, a repair may be fine for now, but it can also be a good moment to think ahead.
If replacement is the better choice, there are things to weigh up, such as the size of cylinder you need, whether it is vented or unvented, and how it connects to your heating and pipework. Our page on hot water cylinder replacement covers that side of things. For leaks that look repairable, you can find out about our help with a leaking hot water cylinder.
A Note on Unvented Cylinders
Unvented cylinders are fed from the mains and work at higher pressure. They have safety devices that should only be dealt with by someone with the right training. Any work on an unvented cylinder needs an appropriately competent professional. If water is coming from the tundish or discharge pipe, get it checked urgently and never block it.
If your cylinder is leaking and you are unsure whether it can be repaired, call Emergency Plumber Swindon on 01793 569521. We can talk it through and take a look at the plumbing side.