Covid 19 update: We are still carrying out repairs and boiler replacements to make sure your heating and warm water is operational and effective. We employ extra safety measures and we make our customers' and engineers' safety a priority.

Why is my boiler leaking?

Wondering why your boiler is leaking?

Your boiler could be leaking because of several things, including pressurisation, damage or wear and tear of the parts inside or the connecting pipework. You need to get to the bottom of why it’s leaking to stay safe, but also to keep your central heating and hot water running reliably.

Discovering your boiler is leaking can be troubling, but there’s probably no need to panic. It might be something you can fix yourself, but it could mean your boiler needs to be serviced, repaired or replaced.

The safest thing to do is always to call out an approved boiler specialist to have a look at it if you’re unsure in any way.

There are several tell-tale signs of a boiler leaking:

  • A puddle underneath the boiler
  • Seeing or hearing drips or a stream of water beneath the boiler
  • Damp walls behind and beneath the boiler
  • Mould or mildew developing on the walls underneath the boiler

The most common reasons for a leaking boiler (and common fixes)

Boilers have two sources of water flowing through them:

  • the water that cycles round the central heating system and passes over the flame
  • the water that goes from the mains to the hot taps and showers

Most leaks come from the internal cycled water, and you can tell if the water is discoloured that it’s probably not fresh from the mains.

If your boiler is old or hasn’t been serviced recently, there’s a good chance something has failed or is about to fail, so you’ll need to call a boiler specialist. If it’s new or recently serviced, it might be an overpressurising issue, which you can possibly fix yourself. Here are the main culprits.

Too much pressure

Your boiler should have a pressure gauge on it, which will either be analogue (a needle, like a speedometer) or digital (a readout like a calculator).

Consult your boiler’s handbook, and find out what the operating pressure is – it’s usually around 1 bar. If it’s way higher, the boiler’s pressure relief valve might be opening, which will cause drips. Bleeding a radiator can cure this.

A faulty expansion vessel

The expansion vessel keeps the water pressure constant as it is heated and cools. It can sometimes jam or fail, which can result in a leak.

Pipework seals

Wherever pipes are joined together, various materials and components work together to keep the joint sealed. These can perish or loosen so need fixing or replacing.

Faulty pipework or component

There are several metres of pipework inside the boiler, plus valves, pumps, the heat exchanger and other components. Any of these can fail, so will need replacing.

An ageing boiler

Nothing lasts forever, and your boiler is no exception. Even if you have it regularly serviced, a boiler will probably last 15–20 years maximum. It’s often cheaper to have a new boiler installed than to continually fix it – and it’ll be more efficient.

Has your boiler seen better days?

If your boiler keeps breaking down, losing pressure or tripping out, it might be time to get yourself a new one. Duffy can replace yours for less than you think, and you’ll start saving money as soon as it’s installed.

Get in touch with our friendly team today on 087 122 1728. We’d be more than happy to discuss your boiler issues, and come to a solution that gets an issue resolved as efficiently as possible.

Published: 2 November 2020

Read More About Boiler Replacement

Should I leave my boiler on all day?

Should You Be Leaving Your Boiler On All Day?

Behind the question ‘should my boiler be running all the time’ is the real question: how can I keep my energy costs as low as possible? There are many ways to keep your house running as efficiently as possible.

Read More

Are gas boilers going to be phased out in Dublin?

Are gas boilers going to be phased out in Dublin?

Is it true that gas boilers are going to be phased out in Dublin? While gas boilers are not being installed in new-build homes, they will not be phased out for many years.

Read More

What size boiler do I need?

What Size Gas Boiler Do I need For My Home in Ireland?

There are all sorts of reasons why you might need…

Read More

Why We Recommend Ideal Boilers

Picture credit: Ideal Boilers If you need…

Read More

Boiler repair

Why Replacing A Boiler Is Better Than Repairing It

Winter’s here – and the last thing you need is a cold house and…

Read More

Gas boiler replacement in Dublin

The 10 Main Benefits of Installing a New Gas Boiler

Do you wince when you look at your gas bill? Do you have to fire up the central heating every time someone needs a bath? Do you wish your house was always warm when you get home from…

Read More