emergency
Boiler leaking — Same-Day Plumber Across the North West
A leaking boiler is a pressing concern, and our local engineers are ready to help resolve it safely.
In short
A leaking boiler can indicate several issues, from minor wear to more significant internal failures. Your immediate priority should be to ensure safety and prevent further damage. KJ Plumbers provides a fixed-price diagnostic service to accurately identify the cause and propose a complete solution.
Tell KJ what's wrong
Free and no obligation — we'll get a qualified local plumber on it.
KJ Plumbing Expert · Online now
KJ
onlineHonest UK plumbing advice — free, and a local plumber when you need one.
Hi, I'm KJ — honest UK plumbing advice, free, and a local plumber when you need one. Tell me what's happening — leak, blockage, boiler, emergency, anything — and I'll help you sort it.
You can send a photo, short video, voice note or share your location — whatever's easiest. Please avoid sending faces, documents, house numbers or payment cards in photos.
For genuine emergencies call 01706 318200, or the National Gas Emergency Service on 0800 111 999.
Start with one tap
Do this right now
Immediate steps to keep you safe
Turn Off Your Boiler
Locate your boiler's power switch, typically a fused spur switch near the boiler on the wall, and turn it off. This is important for safety and to prevent electrical damage.
Turn Off the Water Supply
Identify the main stopcock for your property and turn off the water supply. This will prevent more water from entering the system and minimise further leakage.
Contain the Leak
Place buckets, towels, or other absorbent materials under the leak. This helps protect your flooring and furniture from water damage while you wait for assistance.
Do Not Attempt DIY Repairs
Boilers are complex and contain both gas and high-pressure water. Attempting to fix a leak yourself can be dangerous and may worsen the problem. It's always best to call a qualified professional.
Common causes
What's usually behind boiler leaking
Pressure Relief Valve (PRV) Issues
The PRV is a safety device designed to release pressure if it becomes too high. If the PRV is discharging water, it indicates an over-pressurisation issue within the system, potentially due to a faulty expansion vessel or valve.
Loose Pipe Connections
Over time, the seals and fittings on pipes connecting to and from the boiler can degrade or loosen. This can create small gaps through which water can escape, often visible as drips from pipe joints.
Corrosion within the System
Internal corrosion, often caused by untreated system water, can eat through the boiler's heat exchanger or pipes, leading to pinhole leaks. This is a common issue in older boilers.
Faulty Pump or Diverter Valve
Leaks can sometimes originate from a failing pump seal or a malfunctioning diverter valve. These components move water around the system, and their failure can lead to internal leaks that become visible externally.
Cracked Heat Exchanger
The heat exchanger is a critical component where heat is transferred to the water. Cracks can develop due to thermal stress or corrosion, resulting in water leaking directly from the boiler's core. This is a serious and costly fault.
How KJ handles this
What happens when we're on-site
- 1
Initial Safety Checks and Area Assessment
Our engineer will first ensure the area is safe, checking for any immediate hazards, and then carefully assess the boiler and the surrounding pipework to locate the source of the leak.
- 2
Making the System Safe
Before any diagnostic work, the engineer will permanently make the system safe, which might involve further isolation of water or gas to prevent any ongoing risk or damage.
- 3
Comprehensive Diagnostic Investigation
Using their expertise and diagnostic tools, the engineer will methodically trace the leak to its origin, identifying the root cause, whether it's a component failure, a loose connection, or internal damage.
- 4
Providing a Clear, Written Quotation
Once the problem is identified, you will receive a detailed, written quotation for the necessary repair, outlining all parts and labour required before any work proceeds.
- 5
Efficient and Professional Repair
Upon your approval, the engineer will proceed with the repair using appropriate tools and parts, aiming to restore your boiler to full working order safely and efficiently.
- 6
Post-Repair Testing and Checks
After the repair, the engineer will thoroughly test the boiler and the system to ensure the leak is fully resolved and that all components are functioning correctly and safely.
Where we cover
North West England — same-day where possible
FAQ
Frequent questions
My boiler is dripping, is it an emergency?
Any water leaking from your boiler should be treated as an urgent issue. While a small drip might not seem critical, it can indicate a more serious underlying problem and can lead to water damage or boiler breakdown if ignored. It's always best to have it checked promptly.
How long does it take to fix a leaking boiler?
The time required depends entirely on the cause and complexity of the leak. A loose fitting might be a quick fix, whereas a faulty heat exchanger could take longer due to parts ordering and a more involved replacement process. Our engineer will provide an estimated timeframe with your quotation.
Can I try to fix the leak myself?
We strongly advise against attempting to fix a boiler leak yourself. Boilers involve gas, high-pressure water, and electricity, posing significant safety risks for untrained individuals. Incorrect repairs can also worsen the problem or invalidate any warranty. It is safest to call a qualified professional.
What does the £50 diagnostic cover?
Our fixed £50 diagnostic fee covers the engineer's visit to your property, their time to thoroughly assess your leaking boiler, identify the precise cause of the problem using their expertise and tools, and provide you with a written quotation for the necessary repairs, all without obligation.
What if the boiler is irreparable or too expensive to fix?
If our engineer determines that your boiler is beyond economical repair, or if the repair cost is prohibitive, they will advise you honestly. The £50 diagnostic fee still applies for their time and expertise in making that assessment, and they can offer advice on next steps.
Is a leaking boiler dangerous?
Yes, a leaking boiler can be dangerous. Besides potential water damage, leaks can affect electrical components, leading to short circuits. If the leak is internal, it could impact the safe operation of the boiler, especially concerning the combustion process. It's important to address it quickly.
Ready to get it sorted?
Tell KJ what's happening and get a plan in seconds.
Photos, video and voice notes welcome. Vetted local engineers · no call-out fee · written quote before any repair.