Central Heating / Boiler Magnetic Filter: Installation & Maintenance

Not sure what a magnetic filter is, or not sure if you need one? Read our article below that includes everything about magnetic filters, how they work, how to clean a magnetic filter on a boiler and where to fit them. We’ll also include the installation of magnetic filters, something that PHS can provide you with.

What is a boiler magnetic filter?

Central heating or boiler magnetic filters can be installed at any time and they could really help extend your boiler’s life. But what exactly are they?

Essentially, the clue is in the name, a boiler magnetic filter is a purpose-built magnet for your boiler which helps collect any sludge that can cause dire problems for your central heating system and radiators later in the asset’s lifespan.

How do central heating magnetic filters work?

Simply put, magnetic filters are there to collect sludge.

But what is sludge?

Sludge is the general term giving to all the build-up and particles that have corroded off from inside your system, radiators, pipes etc that accumulates over time.

This usually brown or black sludge that goes around inside your system has another common name: rust, which we know of course is metallic.

The steel that makes up the majority of your system is prone to corrosion over time because the water we use to run our systems is never completely pure and chemical reactions are always going to occur.

But how do the filters catch the sludge?

The fact that this sludge is metallic is exactly why these magnetic filters for boilers have been developed.

These filters have been built through quite a simple concept and yet what they do is perform an extremely precise clean-up.

They can attract any source of metal that is circulating your system that shouldn’t be and filter it out.

This is excellent as it prevents the sludge from building up in the bottom of your radiators or causing blockages in your pipes, pump or heat exchanger, further down the line.

While a bit of sludge isn’t an issue, a lot of sludge could cost you in the form of new radiators – read our article on radiators that are cold at the bottom to find out more – or an expensive visit from an engineer to perform a power flush.

Not to mention the worst case scenario, of new heat exchangers and entirely new boilers.

Boiler magnetic filter installation – Where do they go?

Install should be done by a qualified engineer to ensure your safety and quality installation is carried out. PHS can provide this service across the Home Counties including Suffolk.

What is the best magnetic filter for central heating?

There are a variety of magnetic filters out there (BoilerMag, Fernox, Sentinel, Adey/Magnaclean etc) some even include filters that can pick up everything else in your system, too even if they aren’t magnetic (i.e. zinc). It’s up to you, your budget and your boiler – PHS can consult you and help you pick the right option for you.

If I’m getting a new boiler will this come already installed?

Probably not, but it’s worth looking into and it’s definitely good to ask your boiler company/engineer/ PHS if a magnetic filter can be fitted at the same time. Not only will this provide you with a healthier boiler for longer, but it can actually increase your boiler’s warranty from particular manufacturers – giving you that extra help and peace of mind.

My boiler’s brand new, it’ll be fine… right?

While older central heating systems are more prone to the sludge build up as they’ve been in existence longer and potentially not been receiving the TLC and services a new boiler might, it should not be assumed that new central heating systems are immune to a sludge-induced fault.

Many newer central heating systems that have been installed over the recent years have actually been made up of components that are far smaller in diameter than traditional, older elements/pipework, for space and cost saving purposes.

This actually means build ups take less time to cause severe issues, so we don’t recommend you go without on any boiler – regardless of its age.

My boiler is a few years old, can I still get a magnetic filter?

If you’re not sure if you already have a magnetic filter, simply ask your engineer next time he’s on site to do your annual service. It is likely you will be able to spot it yourself, as they aren’t particularly hidden, but it is worth asking if you’re not sure. If it does, great.

But if it doesn’t, that’s not the end of the world. The biggest difficulty our engineers face regularly when it comes to magnetic filter post-boiler install is the fact that many people have their boilers encased/stored in some sort of housing or a cupboard and the magnetic filter simply won’t fit in as well.

Benefits of magnetic filter installation

As we’ve already mentioned, a magnetic filter could increase your warranty, but did we mention some manufacturers actually insist on a filter to even validate your warranty? Make sure you read the small print but there are manufacturers out there insisting on the following:

1. The heating system has sludge or magnetic filter installed
2. The heating system has the correct amount of inhibitor in it.

What is an inhibitor?

Some magnetic filters come with a pack of chemicals – if you’re not sure what’s best for your boiler or filter, a member of the PHS team can always advise you.

These chemicals are also known as inhibitors are there to help break the sludge down into more manageable chunks that the filter can pick up.

If your boiler has been without both for a few years, the sludge could already be sitting in the bottom of your radiator and a filter alone won’t be strong enough to make it budge.

Add some inhibitor and the sludge will begin to break down and move more freely around your central heating system.

Cleaning & maintenance of magnetic filters on a boiler

After the installation, there isn’t much maintenance involved (for you!)

The filter will, of course, fill up with sludge over time and it will need ‘emptying’ or cleaning from time to time. We recommend you mention your filter to your boiler engineer during your next service.

While they should clean it as a matter of protocol, we can’t speak for all boiler engineers out there, and they might not – so we recommend you give them a friendly reminder.

At PHS we ensure our expert engineers do a thorough and high-quality job, every time – give us a call if you want to arrange your annual service now.

Boiler Magnetic Filter Installers

If you want to talk to PHS about getting a new magnetic filter or about the installation of a magnetic filter, we are just a phone call away. We can advise on what will appeal to your space, boiler and budget requirements and find something that suits you.

To top it off, we will be able to deploy an engineer within 24 hours to give you peace of mind that you’ve got your boiler’s preventative maintenance on the right track.