What to Check If Your Boiler Is Leaking Water

3 February 2025

If not addressed quickly, a boiler leaking water can lead to several breakdowns and some costly and expensive boiler repairs. Whilst sometimes it can be something small such as a seal or washer in the boiler installation, neglecting leaking water can lead to larger issues in the future. Damage can occur from a boiler leaking water on to electrics or expensive parts such as PCB boards.

Acting quickly once noticing a boiler leaking water can reduce the need for expensive boiler repairs in the long run.

If you notice a water leak coming from your boiler installation it is important to contact a fully Gas Safe registered heating engineer to diagnose the issue.

Why Is My Boiler Leaking?

It is essential to find the root cause as to why the boiler is leaking. Below are the common reasons to guide you in identifying a boiler leaking water:

High Boiler Pressure: You have a pressure gauge on your combi boiler installation, or if you have a sealed unvented cylinders system. If the pressure is too high in your central heating circuit this can cause a leak from your boiler installation. The gauge should ideally read 1-1.5 bar, or your gauge may have a green zone. If your pressure does exceed this range you will need to lose some pressure out of the central heating system. Bleeding radiators will help with dropping your water pressure.
Corrosion in Your System: Especially if your central heating system or boiler installation is older, corrosion can be a common reason for your boilers components to start leaking. Rust and magnetite can build up in the system and can cause your central heating system to leak. If you see signs of widespread corrosion you may need to replace your boiler installation and have the central heating system flushed out or a power flushing. By contacting a fully Gas Safe registered heating engineer they can give you an expert opinion as to why your central heating system is showing signs of corrosion and how to go about removing the debris and magnetite from the boiler and radiators circuit.
Faulty Heat Exchanger: The heat exchanger is one of the main components in your boiler installation. A faulty heat exchanger on a boiler is usually the main indication your boiler is starting to fail. A fully Gas Safe registered heating engineer can change the heat cell, however it can be very expensive boiler repairs and a replacement boiler with some of the new extended warranties a Worcester Bosch Accredited Installer can offer, this can be more of a cost effective way of moving forward.

Is a Leaking Boiler Dangerous?

You must address the boiler installation immediately if there are any signs of a boiler leaking water. You don’t want any water leaking onto any of the boilers electrical components, preventing further issues with your boiler in the future.

How to Fix a Leaking Boiler

Potentially, you can follow these steps to help fix a leaking boiler:

Check the Pressure Gauge: If you find the pressure is too high in your central heating system, bleed the radiators to release some water. This potentially may help the issue.
Inspect Pipe Fittings and Joints: Have a look around your central heating system and dry any weeping joints to check if they are still leaking or dripping. You may be able to tighten the nut with a spanner to seal the leaking joint. If in doubt, consult a fully Gas Safe registered heating engineer to fix the boiler repairs.

If you cannot rectify your issue, or for a more thorough investigation with your leaking boiler, you can contact us at AWP Boiler Installations. We can send one of our expert heating engineers if you are in Birmingham or one of the surrounding areas we cover across the West Midlands.

What You’ll Learn Here

Why Is My Boiler Leaking?

Is a Leaking Boiler Dangerous?

How to Fix a Leaking Boiler

What to Check If Your Boiler Is Leaking Water

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