The logo of adu contractors, indicating they specialize in damage repair services related to water, fire, mold, and storms.
How to Fix a Leaking Boiler

How to Fix a Leaking Boiler

You should never shrug off a leaking boiler. But that doesn’t mean you have to spend thousands replacing the whole appliance!

Follow along with this article to learn why your boiler is leaking and what you can do about it.

Common Causes of Boiler Leaks

It is never a good sign when your boiler springs a leak. The appliance keeps you warm during winter and regulates your home during changes in the weather, so you need it to be reliable.

Unfortunately, even attentive homeowners can have this problem. Let’s break down a few reasons this could happen:

Pressure Problems

Boilers come with a release valve that allows excess pressure to escape when the system needs to regulate.

This valve is not sealed, and small amounts of water coming out indicates it is working well.

However, large amounts of water are a concern and mean there is too much pressure build-up. As soon as the gauge needle turns from green to red, you have an issue.

Cracks and Stress

A boiler by nature warms and cools, therefore expanding and contracting constantly. That expansion will occasionally lead to stress fractures that can cause leaks. This issue will require you to replace the whole body of the boiler.

The rubber seals will also wear down over time, even hardening up and allowing water to slip through the cracks.


Constant hot water running through your machine can lead to corrosion. A corroded pipe is a sure-fire way to get a leak.

Once one area has become corroded, it will spread into the rest of the boiler and lead to permanent damage.

Poor Fittings

If you have a new boiler, the installation may be slightly off, with one or two pipes not lined up as they should be. Even if your boiler is operating normally, this will cause a leak.

Loose joints will need professional tightening to resolve the issue.

Collection Of Various Tools

How to Fix a Boiler Leak

When it comes to stopping a leak on your own, go slow and be careful. There are only so many steps you can take before you need to call in the experts. This is a high-pressure system with the potential to spray scalding water on you.

Try these steps at the first sign of water to stop that leak in its tracks:

Turn off Your Water

By shutting your water supply, the leak will stop. This method is not a long-term solution because you can only live without water for so long! However, it’s a quick fix to contain the damage.

Turn off Your Heat

Since your boiler warms your home, turning off the heat will take the strain off the machine and allow it to cool off and stop working. But in the winter, this may not be a livable solution.

Drain the Water

Run your taps and flush your toilets until there is no more water remaining in your boiler or the leak has stopped entirely.


Always dry off pools of water as fast as you can. Mold will grow in standing water in as little as 24 hours.

How to Prevent Your Boiler From Leaking

Once you’ve stopped the leak, it is time to prevent it from coming back. Only the extreme DIYers should attempt these steps. Always call in a professional if you aren’t 100% confident in your skills to avoid risking injury to yourself.

Apply Sealant

Use a waterproof sealant to seal cracks and fissures. This temporary solution can buy you time until you can call in the professionals.

Tighten Joints

If a fitting seems to be wet or dripping, try tightening it until the water stops.

Bleed The Boiler

Use a screwdriver to open the release valve and collect the (very!) hot water. Steam will come out before the water if everything is working smoothly. Check that the pressure on your boiler remains no higher than two bars.

Get Yearly Check-Ups

The best thing you can do to keep your hot water system in tip-top shape is to have an inspection every year. Have an expert come in and make sure all parts are operating correctly.

Boilers should last around 15-20 years. When was the last time you had someone take a look at yours?


If you need help fixing your boiler, the professionals at All Dry USA are just a call away. With more than a decade of experience fixing boilers and stopping leaks, we are ready to come over and patch them up at a moment’s notice.

Don’t let your leak grow bigger, reach out now and keep your home All Dry!


Before You Go

We know that you'll love our service!

Schedule an inspection with All Dry USA today.


Schedule Inspection