Looking for a better deal on your insurance? Get a quote
Become a registered trader - Join us



Leaking Combination Boiler Overflow Pipe: What You Need to Know

If your overflow pipe is leaking, not only are you losing water unnecessarily, but it may be an indication that you have a problem with your boiler. Your overflow pipe prevents flooding in your home by removing excess water from your storage tank or cistern. Many items of basic plumbing in a home will have an overflow pipe, including toilet tanks, cold water feeds, copper cylinders, baths and sinks, and boilers. First, we will take a look at combination boilers, the most common cause for constantly dripping or running overflows, and what you can do about it.

Combination boilers

Most modern homes have a combination or "combi" boiler. A combi boiler is efficient, providing both heating and hot water without requiring large amounts of space. Unlike traditional boilers, which heat up water and store it in a storage tank until needed, a combi boiler heats water as it is required, providing hot water whenever needed.

Combi boilers are fitted with a pressure release valve, which enables water to be released when the pressure in the boiler gets too high. The overflow pipe is made of copper and goes from your boiler to the outside of your house. The overflow pipe will not release any water unless there is a problem.

If you notice a pipe leaking

If you notice that a pipe from your boiler is dripping outside, double check to see what type of pipe it is first. If the pipe is plastic, it is most likely to be your condenser pipe; the pressure release pipe will always be copper. You may not even be able to see your condenser pipe as often that runs directly to your waste.

Why is your overflow pipe leaking?

There are several reasons why your boiler overflow pipe might be leaking, but most commonly it will be because either the pressure release valve is incorrectly fitted, causing it to let water pass through, or because the pressure within the boiler has got too high as the result of a fault with the expansion vessel.

If you do notice that your overflow pipe is leaking it is best to get in touch with a gas safe engineer who will be able to come and assess the situation. It is important that any engineer you work with is gas registered or that they work in partnership with a gas safe engineer who will certify their work.

You can avoid, or at least anticipate, potential issues with your boiler by getting it serviced regularly. All of the traders registered in Trust A Trader’s online directory have been verified by us. To find a reliable, vetted and rated gas safe engineer near you, take a look at our directory. For more tips and advice, join our friendly community of reliable traders and happy customers on Facebook or Twitter.

Was this useful?