My Unvented Cylinder Is Leaking, What Should I Do?

Water heaters make modern life much more bearable. You’re able to wash dishes in the sink, bathe, and more, without having to heat water for the purpose. However, water heaters are subject to wear and tear, and will eventually degrade and need to be replaced. If you’ve noticed that your unvented cylinder is leaking, it can be a confusing, frustrating time. What should you do?

Check the Temperature

First, check the temperature of the water flowing through the tundish. If the water is hot, you know the leak is from the water heater. If it’s cold, then it’s from the mains. Both situations indicate different potential problems.

Hot water in the tundish often signals a problem with the temperature relief valve, which protects you against overheating. If the water is cold, it means there may be a problem with your pressure relief valve. If the water is warm but not hot, it might signal a problem with the expansion vessel.

Turn Off the Water

Locate your main valve that supplies water to the unvented cylinder and turn it off. This will prevent more water from flowing in and help reduce the potential for damage from further leaks. Not sure where the cut-off is? Look for a pipe that runs into the bottom of the cylinder. There should be a wheel-shaped handle here, although other handle shapes may be used. Turn this off and you’ll cut water flowing into the cylinder. Open a hot tap in the house and let the remaining water in the line drain out.

Turn Off the Electricity

If you have an electric unvented cylinder, whether direct or indirect heating, go ahead and turn off the electricity to the system. You can do this in several ways, depending on your model. First, you can find the power switch on the unit itself and flip it. You can also flip the circuit breaker to off.

Turn Off the Gas

If you have a gas-fired unvented cylinder, you’ll want to turn off the gas (without turning off the pilot light). To do that, you need to turn the valve on the side of the unit “off”. You can also follow the gas line until you find the valve and then turn it off. This will cut the gas to the whole unit, meaning you will need to relight the pilot light when you turn the water heater back on after repairs are made.

Call for Professional Assistance

If your unvented cylinder is leaking, do not attempt to repair it yourself. Under UK regulations, only a G3-qualified engineer should service unvented cylinders for safety. Your next step should be to call a professional to diagnose the problem and repair your water heater.

At EasyFlow, our G3-qualified engineers can quickly arrive at your home, inspect your unvented cylinder, diagnose the problem, and make the repair. We carry the most needed parts on our trucks, so most repairs can be handled right away. Call today to schedule your repair!