If your boiler is leaking, it’s important that you get it fixed as a matter of urgency – avoiding water from reaching the unit’s electrical board and causing a short circuit. after all, this could mean having to buy a new boiler. In winter it’s even more important to act fast as you don’t want the boiler to break down completely and needing to be replaced, which could take days and be very expensive, leaving you with the inconvenience of no heating and no hot water for days.

Why is my boiler leaking?

There may be many reasons why your boiler is leaking and they’re not always obvious, however, there are issues which are common and should be checked first.

Here are 5 of the most likely causes:

1. Fault in the boiler’s pressure or temperature valve

If you see water escaping from the boiler pressure valve, you need to first check if the pressure is too high. The needle gage on your boiler’s pressure display should be at one bar. If the needle is showing above one bar and generally in the red zone, your boiler is over-pressurised.

You can bleed your boiler to bring the pressure down, but in many cases, there is some kind of obstruction in your system – such as limescale. If you suspect that limescale obstruction could be the factor, you need to call a registered engineer to fix it.

You may also see water leaking from the temperature valve, which is likely to indicate that the temperature probe in your boiler has stopped working.

2. Corrosion in your boiler

Boiler or water tank pipes are likely to corrode with time, especially in hard water areas, often resulting in leaks. If only the pipes appear to be corroded, a registered engineer can replace those damaged pipes easily enough. However, if the damage is more serious, a new boiler may be required. If you have to replace your boiler, the good news is that it should be much more efficient than your old one, saving you money in the long run, after the initial replacement cost.

Leaks may be avoided if you top up your system with an anti-corrosion product. Your Gas Safe registered engineer will be able to advise on this.

3. Badly installed pipe fittings

If water is leaking from pipe fittings, your system could be installed poorly. This can happen after a new boiler has been installed, if the engineer fitted poor sealing and has not properly tested for leaks. A registered engineer will be able to assist in repairing these fittings.

4. Corrosion to the heat exchanger

If water is leaking from this mechanism, you may have no choice but to replace the boiler. The heat exchanger is a very expensive part to replace, as well as a difficult repair, which means often it’s more cost efficient to replace the entire boiler.

5. Boiler pump seals

The rubber seals found in a boiler system can, over time, get worn away. It tends to be a problem with older boilers. The rubber seals can be changed by a registered Gas engineer.

Act now but be cautious!

You can probably attempt to fix some boiler leak problems by yourself, however, make sure you do not open the boiler itself or try to repair it as it can be very dangerous.

Once again, in most cases, you should enlist the expertise of a Gas Safe registered engineer in order to stop the leak and have any damage repaired without injuring yourself.