Every fixture in your home must be maintained in top condition, and that goes for your water boiler as well. If your boiler leaks, you should address it immediately because it can lead to further damage if you just leave it be.

Pipes with leaks are always a bad sign, and water boiler leaks can be just as devastating—possibly even worse. Regardless of the cause, it’s vital to get it repaired as soon as possible.

How do water boiler leaks form? How do you fix them? This article will tell you what you need to know. Read on below to learn more.

Why Your Boiler is Leaking

Your boiler should not be leaking if it’s operating correctly. If there are leaks, it could be any of the following reasons:

  • The boiler has a water pressure that’s too high or too low.
  • The joints that connect pipes to the boiler may not have been appropriately sealed during installation.
  • The heat exchanger, which changes cold water to hot water, is damaged.
  • Your boiler system is old, and it may need extensive repairs or complete replacement altogether.

In some cases, a leak can be fixed without replacing the boiler, but this still depends on the type of leak.

How to Know If Your Boiler Has a Leak

Unnoticed leaks tend to make the boiler turn off abruptly because of low pressure. Other times, minor leaks present themselves as a stain or mould that’s nearby the boiler.

On the other hand, a boiler that’s dripping downwards is a sign of a broken heat exchanger. It can also be an internal leak.

Types of Leaks

Most people view water boiler leaks at face value, meaning they just think, “Oh, it’s just water coming out”, but there’s a bit more to it than just that. Depending on where the leak is coming from, you can determine the reason for the leak in the first place.

#1: Leaking from the Bottom

When a boiler is leaking from the bottom, it can be caused by several issues which can be pretty hard to narrow down. These include:

  • A leak from the heating pump
  • A malfunctioning pressure release valve
  • Corrosion from the heat exchanger
  • Problems with the auto-air vent

#2: Condensate Pipe Is Leaking

If a boiler’s condensate pipe is leaking, it could be due to a cracked heat exchanger. This has to be repaired as soon as possible because the water can drain into the condensate pipe, which turns it into hot water. In turn, the hot water causes damage by causing the pipe joints to fail. The only way to resolve this issue is to install a new heat exchanger.

#3: Water Leaks from the Overflow Pipe

This applies to Combi systems—boilers that are water heaters and centralised heating systems for an entire home. If the overflow pipe is dripping, the system may have too much pressure or seal the valve correctly.

The Best Way to Fix Leaks

A Gas Safe engineer is the best person to contact to get your boiler leaks fixed. They’re well equipped with the knowledge and tools to solve the problem, so make sure to try and identify everything that has to do with the leak so that they can determine the best course of action. That said, never attempt to fix a water boiler leak on your own!


A boiler leak isn’t something that must be taken lightly. If you don’t get it fixed, then you’re looking at higher utility bills because water will keep flowing even if you’re not using it. Aside from that, extensive damages can also happen, making the cost of repairs higher.

London Climate Hire has established itself as one of the leading boiler hire companies in London. We take pride in providing our customers with top-quality services, which is why we make sure that our boilers are 100% safe to use. We also go out of our way to deliver as fast as we can whenever we are called. Contact us today to learn more!