Got a boiler leak and need help fast?
We’re sharing our top tips on common causes of boiler leaks, how to fix a boiler leaking water, and when to call in the experts.
Quick summary
- A leaking boiler can be caused by pressure issues, broken seals, corrosion or faulty components.
- Immediate action is important to prevent water damage or safety risks – speak to a Gas Safe registered engineer for the safest option.
- James Frew offers trusted emergency plumbing support across Scotland, with 100+ years of experience.
- For peace of mind, explore our Home Plans by GasSure or use our Instant Quote tool if a new boiler is needed.
Why is my boiler leaking water?
Water leaking from your boiler, whether it’s a drip, a small pool underneath or something more serious, isn’t just inconvenient. It can indicate a range of problems, from minor wear and tear to major internal faults.
Here are the most common reasons for a boiler leaking water:
1. High boiler pressure
If your boiler’s pressure gauge is too high, the boiler’s pressure relief valve (PRV) may be trying to release some excess water and reduce the extra pressure.
How to check:
- Check your pressure gauge. It should sit within the green zone.
- If the pressure relief valve is in the red zone, you may be experiencing high boiler pressure. This means it may need to be bled or adjusted.
What to do:
- If the pressure gauge is in the red zone, start by checking that the filling loop isn’t stuck open and letting water into the system.
- If it’s not, wait for everything to cool down, then bleed your radiators to help release boiler pressure.
- If there’s still too much pressure and the gauge remains in the red, professional help is needed. Phone Frew on 01294 468113 or contact us online now.
2. Corroded pipes or faulty seals
System corrosion can be common in older boiler systems, causing rust and other debris to build up. Corroded pipes can break rubber seals around pipe fittings, which can cause leaking water.
How to check:
- Look for water escaping from visible pipe fittings, boiler pipework or underneath the casing.
What to do:
- If you notice corrosion on individual elements, you may be able to replace these.
- If your boiler’s experiencing system corrosion, you may need to replace the system with a new modern boiler.
3. Faulty heat exchanger
The boiler’s heat exchanger is where it heats cold water using hot gas. Cracks or splits in the heat exchanger may result in internal leaks.
How to check:
- This isn’t a problem you can diagnose yourself. Speak to a heating engineer immediately to investigate the problem.
- Depending on the age and condition of the heating system, a new boiler may be required.
What to do:
- Unfortunately, if you’re dealing with a broken heat exchanger, it may be time to think about a new boiler. Older boilers can often experience broken or cracked heat exchangers over time, so in this case, the most cost effective solution may be a new boiler – get an instant price online.
What should I do if my boiler is leaking?
Here are a few things you can do if your boiler’s leaking:
- Turn off the boiler: To prevent electrical risk and further water damage.
- Check for visible water leaks: Look underneath the boiler or at connection points.
- Turn off your water supply: If the leak is persistent.
- Don’t try to open the casing: Only Gas Safe engineers should inspect internal components.
- Contact James Frew for expert help: We’re here 24/7 for emergencies.
Need a fast fix? Call us now on 01294 468113 or book online.
We’ve been solving boiler problems since 1911
We know how chaotic things can feel if your boiler is leaking – low water pressure, an inconsistent heating system, and not to mention cleaning up leaking water more often than not.
Speak to James Frew for service you can rely on:
- Over 100 years of experience across Scotland
- 24/7 on-demand emergency plumbing support
- Trusted by thousands of households and commercial clients
- Reliable boiler service with Home Plans by James Frew GasSure
- Fast, friendly, Gas Safe registered engineers
- 24/7 on-demand emergency plumbing support
- Flexible boiler replacement options
How we help: emergency boiler repairs & more
Whether it’s a small drip or a full-scale flood, our expert team can help with:
- Emergency boiler leak repairs
- On-demand plumbing services
- Central heating and hot water issues
- Advice on repair vs. replacement
Prevent future leaky boilers
Our Home Plans by James Frew GasSure provide a range of boiler cover options to ensure your boiler system is always working efficiently.
- Annual servicing and safety checks
- Priority callouts
- No hidden costs
- Covers parts, labour and emergencies
Frequently asked questions
Why is my boiler leaking water from underneath?
This often points to corrosion, damaged seals or internal leaks in the heat exchanger.
Professional help from a heating engineer is needed to provide the safest outcome possible.
Is a leaking boiler dangerous?
It can be, especially if it’s dripping near electrical components, your boiler’s electricity supply, or affecting your heating. Even just a small leak can lead to damage or even an electric shock
If you have a leaking boiler, speak to a professional now for support.
Is it better to repair or replace a leaking boiler?
It depends on the age and condition of your boiler.
If it’s older than 10 years, replacement may be more cost-effective and help save money in the long run.
