Engineer looking into the cause of a leaking boiler

Why is my boiler leaking & what should I do?

A boiler leaking water can be a serious problem. A number of factors could be the cause behind your leaking boiler and finding its direct source is the first step in fixing the issue. Boiler leakages are often caused by internal issues and can usually be repaired fairly easily by a Gas Safe Registered engineer. Is a leaking boiler an emergency? A substantial boiler leak or a leak caused by a serious issue could be considered beyond economical repair, which may mean that you would need to replace your boiler. No matter the cause behind your leak, HomeServe are here to help and could provide you with exactly what you need to get your household heating up and running again.


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Top causes of boiler leaking water

1. Pressure problems – If you find that your boiler is leaking from its pressure valve, it is possible that its pressure levels are too high. A boiler’s pressure should usually be between 1 and 2 bars, so when the pressure exceeds this the pressure relief valve will leak water in order to prevent the appliance from erupting. The occasional water dripping from the boiler valve is fairly normal, however should a considerably large amount of water be escaping from the system it could mean that the pipe is working overtime and boiler dripping more often to release excess pressure. Should this be the case, try reducing the boiler’s pressure or alternatively get in touch with us so that we can send one of our Gas Safe engineers who should be able to deal with the problem quite quickly. *


2. Corrosion – This is a common cause of a boiler leaking water within households across the UK. If your boiler’s pipes or tanks become corroded they could weaken and eventually begin to allow water to escape. If it is one, single element of your boiler system that is corroded, such as the valve, you may be able to resolve the issue by getting this part replaced. However, should the corrosion be wide spread and across the whole system, your boiler may be beyond economical repair which could mean that you would have to replace it.


3. Temperature issues – Should your boiler be leaking from the temperature valve, it is possible that its temperature settings are too high. This could be due to a fault with the system’s temperature probe.


4. Impaired seals – When your boiler’s seals are damaged, water can escape through normal use or it could also be possible for the pump to be pushing water out through them. In order to rectify this issue, it is usually best to have both the seal and the pump replaced.


5. Cracks in the boiler body – It is normal for the body of your boiler to develop some flaws over time. The repetitive warming and cooling that takes place within the system will cause the metal to expand and contract, which could eventually lead to a crack or a split. It is usually fairly easy to tell if this is the cause behind your boiler leaking water as the flaw should be visible. Cracks and splits in boilers tend to be serious issues with expensive repair costs so if your boiler is relatively old, it may be best for you to consider getting a new boiler installed.


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6. Installation faults – In our experience, when boilers develop leaks around their pipe fittings, it is usually due to low quality installations where the engineer has not worked to a high standard or followed regulations. The engineers that we employ at HomeServe are all Gas Safe registered and are therefore fully trained and qualified to conduct thorough installations, ensuring that each job has been completed correctly.


7. Loose joints – This is another common cause of water leaking from a boiler. Much like cracks and splits, this problem tends to develop due to hot and cold contraction and expansion. However, this issue is usually easy to fix; you should check all of the boiler’s fittings as well as the pipes and tubes that lead in and out of the system. * Be sure to take a look at the blowdown valve and ensure that it is not loose or damaged. * Alternatively, you can call us to organise a visit from one of our engineers who could easily do the job for you.


All in all, there could be a number of causes behind your leaking boiler and it is important that you get the problem fixed sooner rather than later to prevent the situation from worsening. Here at HomeServe, we have a team of trained, Gas Safe engineers that should be able to fix your leaking boiler, regardless of the cause. Additionally, should your boiler be beyond economical repair, our engineers are able to replace your current boiler with a new, A-rated boiler system from one of the many reputable brands that we work with. We could also offer the option to extend your warranty to up to ten years.



*The above information has been provided by Homeserve for information only and is not a substitute for a qualified engineers assessment or diagnosis. Homeserve is not recommending or endorsing any Do it yourself style boiler fixing as a result of the information provided. All heating systems differ in type (fuel and installation) and repairing electric or fuel appliances may pose a significant risk to health and safety where a person is not suitably qualified to undertake such a repair or diagnosis.


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Information and other materials on this website are not intended to constitute professional advice and should not be relied upon. Please see our Terms of Use for further details.

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