WHY IS MY BOILER LEAKING WATER?

A leaking boiler is a cause of concern for every homeowner. It’s an indicator that your boiler is in need of repair by a professional heating engineer.

There are a variety of issues that may cause your boiler to begin leaking water but thankfully most are repairable.

High Boiler Pressure

One of the more common reasons that your boiler may begin to leak water, particularly from the bottom, is the pressure being too high. Boiler’s have an outlet pipe that is configured to release excess pressure which often causes water to escape. Large leaks suggest that the pressure is too high, while small drips, although not as serious, can turn into bigger issues if they are caused by high pressure.

If you suspect this to be the source of your issue, check your pressure gauge. If the needle sits in the red then your system may need bleeding or repressurising.

Corroded Pipes

Another common cause of a leaking boiler is corrosion. Sludge and debris in the water can wear down pipes underneath the boiler over time, causing them to weaken and even crack causing the leak.

Thankfully a corroded pipe is easily identified and a heating engineer can often replace at an affordable price, provided that the corrosion is limited to a small number of pipes.

Faulty Heat Exchanger

A more serious issue to consider when identifying the source of water leaking form a boiler is a faulty heat exchanger. The heat exchanger is responsible for heating water through your boiler. Over time, repeated expansion and contraction from temperature changes can weaken the metal and subsequently crack.

This is the most expensive component to replace and financially, it often makes more sense to invest in a new boiler instead.

Failed Expansion Vessel

An often overlooked cause of a boiler leaking is a failed expansion vessel. The job of this component is to absorb pressure changes as water heats and cools. An expansion vessel can develop a fault that allows pressure to build and force water out in the system.

A gas engineer can assess the situation to determine if it can be repaired or if a brand new vessel is required.

Worn Out Seals

Boiler leaks can also occur when seals are worn out. As a boiler heats and cools over the years, repeated thermal expansion causes seals to loosen and break. When this happens, water can quickly be released from the system, often causing boiler pressure to drop as well.

A qualified heating engineer can replace broken seals by opening the boiler casing. It is important that you allow a professional to do this rather than removing the casing yourself.