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Why is My Boiler Leaking Water? – 6 Common Reasons You Need to Know

Last updated on: 29 August 2024

Why is My Boiler Leaking Water? – 6 Common Reasons You Need to Know

Is your boiler leaking water, and you don’t know why? Then, no need to worry anymore! In this blog, I will tell you the common reasons why water is leaking from your boiler. Not only that, but I will also tell you solutions that you can follow to solve the problem.

My Boiler is Leaking Water – What Should I Do?

If you inspect the water dripping from your boiler, then please pay attention to the problem and take corrective action. To do that, you must know the reason behind the leakage, which will be discussed further in this blog.

Once you inspect the problem, contact a certified Gas Safe registered engineer immediately. As a legal and safety precaution, you should only attempt to fix your boiler if you are qualified and certified.

Common Reasons Behind Water Leaking From The Boiler

Now you know what to do after inspecting a boiler leakage! But what are the reasons behind it? There could be numerous reasons for your leaking boiler. Below, I am going to mention six of them:

Too much pressure
Corrosion to pipe fittings
Improper installation
Faulty heat exchanger
Internal Leakage
Corrosion and general wear

Let’s discuss them in detail:

1. Too much pressure

Like many other pressure-sensitive devices, your boiler cannot handle too much pressure. High boiler pressure means your boiler uses too much water, causing overflow pipe leaking. The good news is that you can monitor your boiler’s pressure through a pressure gauge on the front of your device.

A boiler’s pressure should be between 18 and 21 PSI, or one bar. And when the pressure exceeds this value, let’s say above 2 bars. The pressure relief valve will leak water to prevent your boiler from imploding. Ensure the bar on your pressure gauge lies between 1 and 2 bars, ideally 1.5.

Although you can solve pressure-related problems, you don’t necessarily require the assistance of a certified registered engineer; all you need to do is bleed out your radiators. To learn how to bleed radiators, read our helpful guide, How to Bleed a Radiator: A Step-by-Step Guide.

2. Corrosion to pipe fittings

A common issue that causes your boiler to leak water is corrosion, especially when your boiler is old. As time passes, pipes underneath your boiler get corroded, due to which your boiler circulates water. This happens because the water in your pipes combines with metallic debris, resulting in natural corrosion and small gaps in the pipework.

However, if your boiler is too old, over 10-15 years old, it is suggested that you invest in a new boiler. As the chances are the faults will occur more frequently due its age. But considering the hefty cost associated with boiler replacement, the short-term solution is to buy metallic filters that have characteristics of resistance against corrosion, high temperature, and pressure.

3. Improper Installation

Let’s say you have a new boiler, but it is still leaking from the pipes. The reason behind it could be poor installation by your engineer. The corrective action in this case is to immediately contact your engineer who installed it and let him know the issue.

4. Faulty heat exchanger

A heat exchanger transfers heat from gas to water. Circulating your home through the radiator. Providing you with heat and hot water. The heat exchanger is one of the most expensive parts of your boiler. In old boilers, the heat exchanger can become faulty and get exposed to damage over time.

In the event of a faulty heat exchanger, you can get it replaced by a professionally certified gas-safe engineer. But as mentioned, the heat exchanger is quite expensive if you don’t have boiler insurance. If your boiler has become too old, getting a new one is better.

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5. Leaks from Internal Parts

Over time, the seals and the pumps may have corroded or decayed. This will prevent them from functioning optimally. Leaving your boiler vulnerable to internal damage. Internal leaks can cause your boiler to leak water rapidly, which can cause a real safety issue in your home.

The suggested solution is to contact a Gas Safe-registered engineer and let him deal with the problem. He will visit your place, remove the cover of your boiler, and perform a detailed inspection to see exactly where the problem lies within your boiler.

6. Corrosion and general wear

This is a common problem that almost all boilers face at some point in time. Sometimes, your boiler leaks water regularly. Indicating that the copper pipes of the boilers have decayed. You can fix it temporarily, but it can cause major problems if not properly repaired.

So, it is best that you leave it to a gas-safe engineer. Plus, start planning to buy a new boiler if yours is over 15 years old. Also, if you are finding it difficult to pay a lump sum amount for your boiler, you can get a boiler on finance.

How To Fix a Leaking Boiler

So far, I have mentioned the reasons that cause leakage and the actions you must take to solve the problem. This indicates that apart from pressure-related leakage problems for all other issues, i.e., faulty internal components, corrosion, wear and tear, and improper installation, you must contact a Gas Safe Engineer.

If a pressure-related problem causes the leakage in your boiler, let’s say the pressure is too high, then relieve some pressure by bleeding out your radiators and re-pressurising them via a boiler filling loop.

If you see water leaking from a pipe joint, then it indicates that the joints are loose. You could try to tighten it. If the leakage in your boiler is minor and evident, you could also use leak sealants, which are additives you add to your central heating system and seal the hole automatically. But before adding sealants, you must still consult a professional.

Is A Leaking Boiler Dangerous?

A leaking boiler is a serious situation that requires immediate attention. Negligence towards this problem can make it dangerous, resulting in potential structural damage to your home and health. In the worst case, the buildup of leakage can cause your boiler to explode.

How Can I Prevent Leakage in My Boiler?

However, there is no such guarantee to prevent the leakage, as it could be due to your boiler’s old age or human error resulting in poor installation. Moreover, there are a few steps that you can take to avoid leakage problems in your boiler, possibly:

Get an annual boiler service; it is a great way to maintain your boiler, minimise boiler faults, keep it under warranty, and keep it running optimally. If you have a boiler cover, it might be included in your policy. Otherwise, you can schedule it from 24|7 Home Rescue by clicking here.

Consider getting a central heating power flush, which removes the sludge and rust buildup from your system by connecting it to a powerful external pump. Then, it releases chemical agents to remove debris, slime, and rust buildup.

Another option is a chemical power flush, which differs from a power flush as it does not require power. Instead, cleaning agents are released in your system and flow around with the natural flow of water and gravity, which removes the rust, debris, and slime buildup.

Lastly, get magnetic filters added to your boiler by a gas-safe engineer. Magnetic filters help prevent the buildup of debris that forms sludge.

Common Error Codes for a Leaking Boiler

Brand	Error Codes
Worcester Bosch	A1, E9, CE207, HO7
Vaillant	F.22, F.24, F.13, F.73, S.41, S.53
Baxi	117, 118, 125, E78, H.02 – 06
Ideal	F1, L1, FD

You can learn more about the error codes for all major types of boilers on this category page.

Final Words

Here you go! After reading thus far, you now know the common reasons behind your boiler leakage, the possible solutions, and the preventive measures. However, if you require further assistance or want to book a boiler repair or an annual boiler service, please get in touch with us at 0345 3192 247.

FAQ’S

Why is my boiler leaking water from the bottom?

When your boiler leaks water from the bottom, the pipes underneath it have corroded naturally or may be due to improper installation.

If your boiler is old, it is normal to experience leaking over time. The water in the pipes is combined with metallic debris. This results in natural corrosion. Corrosion can lead to small gaps in the pipework. And this will cause the water to leak out. To avoid this, buy a metallic filter today.

If I turn my boiler off, will it stop leaking?

If you turn off your boiler, the leaking will stop as the heat increases the pressure. Thus, the weak point is more exposed and starts to leak rapidly. By turning the boiler off, the pressure will drop. Providing the system with enough time to cool down.

Is it normal for a boiler to leak water?

If your boiler is around 10–15 years old, it is normal to leak over time. The reasons are corrosion, lack of boiler maintenance, and general wear.However, if your boiler is brand-new, the engineer may have done a poor job of installation. So, call them immediately and let them know the issue. And get it solved.

The information provided in this article has been collected from various sources. However, we suggest you consult a certified Gas-Safe Engineer in your area before making any decisions, as every individual’s home situation is unique.

Posted by: Martin Astley 25 October 2022