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What To Do If Your Boiler is Leaking Water

Identifying Boiler Leaks, Assessing Risks, and Taking Action

A puddle beneath your boiler is never a welcome sight. Is it a minor issue, or is your home at risk? Should you grab a wrench, or are you better off calling a professional? If you’re wondering what to do if your boiler is leaking water, you’re in the right place.


The Simply Plumbing team, based in South Bedfordshire, are trusted local experts with over a decade of experience, and we’re here to guide you through every step. We’ll take you step-by-step through everything you need to know:


  • Understanding WHY your boiler might be leaking (and the most common causes)
  • How to assess the severity of the leak
  • DIY solutions (if appropriate)
  • When it’s time to call in the experts

Our goal? To give you the information you need to make the best decision for your safety and your family’s wellbeing. Let’s tackle this leak together!

Why is My Boiler Leaking Water?

A leaking boiler is not something to ignore. Even a small leak can signal a bigger problem and cause damage to your home. If the leak is substantial or accompanied by strange noises, turn off your boiler immediately and call Simply Plumbing for our emergency service.


The Age Factor:


  • 20+ Years Old – In older boilers, leaks often signal that its lifespan is coming to an end. Parts wear out, seals deteriorate, and internal corrosion can occur. While repairs might be possible, a replacement may be the most cost-effective and safest option.
  • 10-19 Years Old – Boilers in this age range certainly still have some life left in them, but leaks could indicate the start of more frequent breakdowns. A professional heating engineer can help you decide whether repairs are cost efficient.
  • Under 10 Years Old – Leaks in newer boilers are less common but can still happen. They’re usually caused by specific issues that can be fixed.

Common Culprits Behind Boiler Leaks:


  1. Pressure Relief Valve – This valve is designed to release water if the pressure inside your boiler gets too high. If it’s faulty, it might leak even when pressure is normal.
  2. Corrosion – Over time, internal components can corrode, leading to leaks. This is more common in older boilers or systems operating with hard water
  3. Temperature/Pressure Problems – Fluctuations in temperature or pressure can stress the system and cause leaks.
  4. Pump Seals – The seals in your boiler’s pump can wear out and leak.
  5. Loose Joints or Connections – Sometimes, it’s as simple as a loose pipe or fitting that needs tightening.
  6. Cracked Heat Exchanger – This is a serious issue and requires immediate professional attention. The heat exchanger transfers heat from the burner to the water, and a crack can lead to dangerous carbon monoxide leaks.

Important Note: If you smell gas or suspect a carbon monoxide leak, evacuate your home immediately and call the gas emergency service.

Assessing the Severity of Your Boiler Problem

Assessing the Severity of Your Boiler Problem

Now that you understand the potential causes, it’s time to consider how serious your leak is. Before you do anything, think about safety. If the leak is substantial, creating a puddle or spraying water, or if you smell gas or hear unusual noises, turn off the boiler immediately and call Simply Plumbing.


If the leak seems minor, you can carefully try to pinpoint its source. Look for drips, damp patches, or water pooling around the boiler or its pipes. Note the location of the leak and how much water is escaping. Is it a steady drip or a slow trickle? The amount and location of the water can help determine the cause and urgency.


Check the boiler’s pressure gauge. If it’s reading below 1 bar, the leak might be affecting the pressure in the system. However, a high pressure reading (above 3 bars) could also indicate a problem and require professional attention.


Remember, this assessment is no substitute for a diagnosis from a Gas Safe heating engineer. Even if you identify the source of the leak, it’s important to have a qualified plumber confirm the cause and recommend the best course of action.

DIY Fixes if Your Boiler is Leaking Water (Where Appropriate)

Some minor leaks can be solved with simple DIY measures. However, it’s crucial to remember that these are only suitable for very minor leaks and should never be attempted if you’re uncomfortable with DIY plumbing. If you’re in doubt, call Simply Plumbing for professional assistance.


1. Tightening Loose Connections:


  • Check – Look for drips around visible pipe joints or connections.
  • Tighten – Carefully tighten any loose nuts with a wrench. Avoid overtightening, as this can damage the connection.

2. Checking the Pressure:


  • Locate – Find the pressure gauge on your boiler.
  • Ideal Pressure – The pressure should typically be between 1 and 1.5 bar when the boiler is cold.
  • Adjust – If the pressure is low, you might be able to top it up using the filling loop (consult your boiler’s manual for instructions). If the pressure is high, DO NOT attempt to adjust it yourself – call a professional.

3. Bleeding Radiators:


Important Safety Note:


  • Electricity – Always turn off the boiler and let it cool down completely before attempting any DIY fixes.
  • Gas – If you smell gas or suspect a gas leak, leave the property immediately and call the gas emergency number.
  • Water – If the leak is substantial or you’re unsure about any step, do not attempt to fix it yourself. Call Simply Plumbing for expert assistance.

Remember, your safety and the well-being of your home are paramount. When in doubt, trust the professionals at Simply Plumbing.

When to Call in the Professionals – Don’t Risk It!

In conclusion, while minor boiler leaks can sometimes be addressed with DIY fixes, it’s crucial to put your safety first. If you’re uncertain about the cause of the leak, its severity, or how to proceed, don’t hesitate to contact Simply Plumbing.


Our heating engineers will assess the situation, accurately diagnose the problem,  and recommend the most appropriate action. Whether it’s a simple repair, a component replacement, or a boiler upgrade, we’ll ensure your home’s heating system is safe, reliable, and efficient.

Don’t let a leaking boiler disrupt your comfort and peace of mind. Contact Simply Plumbing today for expert guidance and solutions. Your safety and satisfaction are our top priorities.

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