Is your boiler pressure dropping?

Boiler Pressure Loss On GuageModern boilers and heating systems are pressurised – and they rely on this pressure to make sure every radiator in your home warms up when needed.

Normally, a boiler will keep its pressure for months without needing to be topped up – so, if the dial on your boiler is indicating that the system pressure is low, it could mean you’ve got a leak and therefore loss of boiler pressure.

Before we explore how to fix a boiler leak, it’s worth understanding a little about your system – and working through a few things you can do to solve pressure problems yourself.

What is boiler ‘pressure’ and why does it matter?

There are lots of technical reasons why boiler pressure matters – but, most importantly, keeping the correct pressure in your boiler means you’re able to warm your house and run hot water!

Usually, you’ll be able to check your boiler pressure by looking at the gauge on the front.

If you’ve got a digital gauge, there will be a flashing light or a warning that says “Loss of pressure detected”.

Boiler Pressure Guage (Analogue)If you’ve got a dial, the needle should be pointing to just over 1 bar of pressure when the radiators are cool, and around 2 bar of pressure when the heating’s on. If it’s lower than 1 bar when the radiators are cool, there’s a good chance the pressure’s too low.

It’s actually only your central heating that requires system pressure. This pressure is needed to make sure heat is spread evenly through your home. If the pressure is too low, your boiler is designed to cut out – protecting its internal components from becoming too hot. In this case you may require our specialist central heating leak tracing services.

The trouble is, when your boiler cuts out, it also stops heating the water that comes out of your taps – so low pressure doesn’t just mean no heating – it also means you can’t run a bath or do the washing up.

What kind of problems can a leaking boiler cause?

At best, a leak will mean a cold shower and mopping up water leaking from under your boiler – but be warned; leaks can often lead in big problems, including the spread of damp through the structure of your home – and significantly increased water bills.

Since almost all of the central heating pipes that run to and from your boiler are hidden, leaks can go unnoticed for a long time. Therefore, it’s important you never just ignore pressure problems – whether that’s a leak you can see (like a combi boiler’s pressure relief valve leaking outside) or simply finding that your boiler is shutting down frequently.

Why does boiler pressure drop?

Most modern heating systems are based on a ‘closed-loop’. This really just means that the pressurised water is trapped in the pipes and radiators that are in your house.

Very occasionally, some of the more sensitive parts of your boiler can become damaged or worn, and this can result in dropped pressure. However, low pressure in your boiler almost always comes as a result of either air or a leak somewhere in this closed-loop.

How to fix a leaking boiler

There’s no one-size-fits-all when it comes to fixing a low-pressure boiler. There are some easy fixes – and some which require the help of specialist leak detectors. That said, trapped air in the system is usually an easy problem to solve – so that’s the best place to place to start.

First, check your radiators

Radiator Leak Causing Boiler Pressure Loss - Being RepairedAir in your radiator system is a common cause of low boiler pressure – and it can creep in if you’ve had recent work done to your home’s heating.

Fortunately, getting the air out is a simple task. You’ll need to use a bleed key to open the vent on the radiator. If you open it too much, you’ll release water; so do it carefully – and keep a towel to hand as water will follow when the last of the air escapes. Repeat this process with every radiator in your house.

Topping the pressure up

Making sure your radiators are free of air might stop your pressure dropping – but it won’t bring the pressure back up to the correct level. To do that, you’ll need to use the ‘filling loop’.

Since all boilers are slightly different, it’s worth looking at your instruction manual or consulting the boiler manufacturer’s website to make sure you’re doing this correctly. Usually, you’ll need to:

  • Turn your boiler off and wait for it to cool
  • For ‘external’ loops, securely fix both ends where indicated
  • Open the valve on the loop, allowing water to enter the system
  • Let the pressure top up to 1.5 bar
  • Close the valve
  • Switch on/restart your boiler

Overfilling your boiler can lead to damage, so you should only add water with the filling loop if you’ve checked your instructions and you’re confident to do so.

What should you do if your boiler pressure drops again?

If bleeding your radiators and topping up your system pressure only works for a short time, this would indicate that you’ve got a leak – either in the boiler or somewhere in the connected pipework.

You might be tempted just to top the boiler back up again – but it’s important you don’t keep doing this. The water that’s inside your closed-loop system actually has a blend of chemicals mixed through it. These chemicals are referred to as an ‘inhibitor’.

This inhibitor fluid prevents the build-up of corrosion and sludge in the system – and if you keep topping the system up, you’ll water this down, potentially shortening the life of your boiler and pipework.

So, what should you do instead?

We’ll help you find the problem

Unfortunately, simply having your boiler serviced is unlikely to fix your leak problem. The Gas-Safe Engineer you use will do a great job of checking the boiler itself – but you’ll need specialist equipment to assess the full extent of the leak.

At ADI Leak Detection we specialise in leak detection. We do not stop until we’ve found the source of the problem.

The Original Water Leak Detection CompanyOur innovative way of working means we can offer completely non-destructive leak detection – so we have no trouble working around any kind of flooring, including:

  • Carpeted floors
  • Wooden or laminate flooring
  • Vinyl flooring or tiles
  • Ceramic tiles
  • Lino flooring

In fact, we’re yet to find a floor that we can’t work through. We can even detect leaks under industrial and commercial flooring. Quite simply; the location of your boiler and pipework won’t stop us getting the job done.

What’s more, we’re always happy to help you with any associated insurance claims – and we’ll provide photographic reports, so you can be sure that only the necessary work will take place.

What’s the next step?

If you’ve got a leak, it’s important that you deal with it quickly – before it causes further damage and costs you money.

Call us now on 0800 731 3843, You’ll speak to one of our friendly team, and we’ll help you deal with your boiler pressure loss today.