Is a Leaking Boiler Dangerous? What You Should Do

Seeing water dripping from your boiler is understandably worrying. The good news is that most boiler leaks are not dangerous in themselves, but they do need fixing before they cause further damage. Here is how to assess the situation and what to do next.

Is it dangerous?

A water leak from a boiler is not the same as a gas leak. Water dripping from pipes, valves, or the boiler casing is not going to explode or poison you. However, water and electricity do not mix. If water is dripping onto electrical components inside the boiler, it can short circuit the PCB (the boiler's main circuit board), which is one of the most expensive parts to replace.

If you can smell gas as well as seeing water, that is a completely different situation. Leave the house immediately, do not touch any electrical switches, and call the National Gas Emergency number on 0800 111 999.

What to do

1. Turn the boiler off at the controls. Do not try to open it up
2. Turn off the water supply if the leak is significant. The stopcock is usually under the kitchen sink
3. Put a towel or bowl underneath to catch the drips and protect your floor or any items below
4. Note where the water is coming from — this helps the engineer diagnose the problem faster
5. Do not attempt to fix it yourself. Boiler internals should only be accessed by a Gas Safe registered engineer

Common causes of boiler leaks

• Pressure relief valve dripping — the copper pipe on the outside wall is wet. Usually means pressure is too high or the expansion vessel has failed
• Pump seal failure — water leaking from around the pump area underneath the boiler
• Corroded heat exchanger — internal corrosion causing a slow leak. More common on boilers over 10 years old
• Loose pipe connections — joints can work loose over time due to thermal expansion

Most boiler leaks are straightforward repairs. The key is to catch them early before water damage makes them more expensive.

Need help with your boiler? Our Gas Safe registered engineers cover the North East. Get in touch today or call 0191 540 2051.

The bottom line is that a leaking boiler should never be left to drip, as even a slow leak can damage the boiler and your home over time.