Are Magnetic Filters Worth It?

Are Magnetic Filters Worth It? | A Definitive Guide

Are Magnetic Filters Worth It? The purpose of this useful component is to catch most of the sludge that circulates around your heating system. If ignored, this sludge – which can be a mix of metallic and non-metallic deposits – can build up to the point where your radiators have cold patches, your boiler’s efficiency is drastically lowered and your energy bills are raised. Gone on long enough, a combi boiler problem such as this would only get worse.

Even though the answer to the question ‘Are Magnetic Filters Worth It?’ seems to be a definitive ‘yes’, it’s just as important to know why.

If you’re a homeowner, you may have heard about these from a friend, a family member or even another installer. Yet if you’re unsure on what they do and how they work, things can get a little overwhelming. If this is what you’re currently going through, you can relax – what you save in the long run with a magnetic filter makes it more than worth it. Ultimately, you’re trying to make your boiler last as long as possible. You shouldn’t have to worry about constant repairs with every service. Components like a magnetic filter can help extend your boiler’s lifespan and reduce your energy bills.

Are magnetic filters worth it? Yes they are!

In this article, we’re going to cover the following points:

  • Why you need a magnetic filter
  • How a magnetic filter works
  • Examples of current filters on the market

By the end, you’ll have all the information you need to answer the question ‘Are Magnetic Filters Worth It?’

For more problem-solving help and information, take a look at some of our other blogs:

Let’s take a look!

Why do I need a magnetic filter?

Even though the name is a bit of a giveaway, you may be asking ‘Are Magnetic Filters Worth It?’ as well as why you need one in the first place, and where the problem comes from. The truth is, you must make sure that when you have a new boiler installed, you get a magnetic filter fitted as well.

Having a magnetic filter installed has its own benefits that include:

  • Annual energy bills reduced by up to 6% (3-bedroom example)
  • Boiler’s efficiency is drastically improved
  • Reduced likelihood of expensive repairs
  • Lifespan of boiler extended
  • Carbon footprint reduced

Over time, your central heating system can fall victim to corrosion and rust. When this occurs, tiny particles from the deposits eventually collect to form a dark sludge.

Sludge deposits make it difficult for your system to operate to its full potential, so a magnetic filter will be needed

On occasion it can also produce a unusual dark orange colour – this is a direct result of internal rusting that can sometimes occur. The sludge is left to either sit at the bottom of your radiators, or clog up your pipework and other areas of your heating system.

Sludge deposits cause cold patches to form at the bottom of your radiator

Side Effects

If you don’t get this sludge removed, there can be some troublesome side effects, another reason to ask yourself ‘Are Magnetic Filters Worth It?’:

Side effects of not having a magnetic filter installed

Nobody wants a broken boiler, but these things can happen they’re not taken care of!

Your magnetic filter deals with this by collecting the dirt particles as they’re coming through the system. It holds onto them until it’s emptied – whether this is done every few months or during your annual service will depend on aspects like age and condition of the current system.

What happens if I don’t have a magnetic filter installed?

This one can also answer the question ‘Are Magnetic Filters Worth It?’. If you choose not to have a magnetic filter installed, the most significant consequence is that you could invalidate your manufacturer’s warranty – as well as your energy bills continuing to rise. This is because your radiators are no longer able to heat at full capacity due to the magnetic sludge in your system. If the efficiency of your boiler is affected too much, you may have to consider a replacement. This can be scary, but the good news is that getting one fitted is extremely easy.

It’s clear at this point just how many benefits there are with having a magnetic filter installed. However, if you choose not to have one, be aware that magnetic sludge will still continue to form.

If your system is already filled with sludge, you’ll need one of three types of flush performed:

  • Chemical Flush
  • Power Flush
  • Advanced Flush

All of these need to be carried out by a visiting professional, and involves pumping chemicals through the pipes, radiators and boiler to get rid of any limescale or magnetic sludge deposits. This is a reasonably long process usually taking several hours, and is often the more expensive option.

When any of these are carried out, your system will need to be dosed with inhibitor to keep the pH levels of the water reasonable. This slows and prevents the build up of magnetite sludge once you’ve got your system cleaned. After this, simple water tests are a useful way of finding out if they’re successful.

If the damage is built up enough over time, then the worst case scenario is that your system needs to be replaced.

Can I install one on the system I already have?

Commonly in 2019, most magnetic filters are installed at the same time as your boiler, but it’s still possible to have one fitted on an already existing system. When considering the question ‘Are Magnetic Filters Worth It?’, finding the answer can be incredibly easy by looking at what can happen if you don’t have one installed. However even though you have the choice, if you’re having a brand new boiler installed, make sure that without fail it has a high quality magnetic filter as part of the quotation. If you know you’re not getting a filter straight away, be sure to communicate very clearly beforehand that you want to keep your options open. You’ll have to take into account space for maintenance and the filter around the boiler as well.

Do I need to clean my magnetic filter?

The frequency of how often you should monitor the sludge in your system filter can vary. However, best practise is to check during the boiler’s annual service. When they’re full of sludge, some magnetic filters can affect the performance of the system due to reduced flow rate. So if you’re feeling unsure, it’s always best to have a professional clean it out. If you’ve recently had a power flush or you’re aware of sludge already sitting at the bottom of your radiators, you may find that the filter can pick up a lot more during its first period of operation.

Once you’ve cleared out most of the sludge from your system, it doesn’t need to be emptied as often, and can simply be done during your annual boiler service.

Examples of Magnetic Filters

When learning about ‘Are Magnetic Filters Worth It?’, it pays to know about the brands that are currently available on the market. As much as we can learn about how magnetic filters actually work, the following list is a selection of some of the main brands available:

Spirotrap MB3

Manufacturer: Spirotech

Spirotech has a track record of designing and manufacturing excellent products in the central heating industry. Their magnetic filters are brass in construction and provide outstanding results for helping you clean out your system.

By learning from previous iterations of their ‘MB’ line, Spirotech has made several improvements to the filter design, making them a strong competitor.

How does it work?

The Spirotrap MB3 uses a removable magnet and spirotube element to make up its unique dual separation system. With this design, magnetic and non-magnetic particles are collected and filtered out, making your system a lot cleaner. The filter itself contains a unique magnetic field booster which extends the filter’s dirt collection capacity, meaning it can remove more dirt, more quickly.


  • 20-year guarantee
  • Magnet part boasts magnetic field booster technology
  • Easy installation
  • Duel action technology removes magnetic AND non-magnetic deposits
  • Increased flexibility on where filter can be positioned on pipework
  • Maintenance only takes a few seconds
  • Spirotrap also state that there is no flow loss on their filters

Magnaclean Atom

Manufacturer: Adey

Much like the previous filter, the Magnaclean Atom helps protect your central heating system from the negative effects of black iron oxide sludge. With a compact design, it can be installed in most areas, even if your boiler has already been fitted. It can also be fitted onto vertical or horizontal pipework and comes fully supplied ready to be installed on the day.


  • Carbon emissions are reduced
  • Save up to 6% on annual energy bills
  • Lifespan of heating system extended
  • Needs only 115mm to be installed even in the smallest of spaces

Fernox TF1 Compact Magnetic Filter

Manufacturer: Fernox

The TF1 Compact uses hydrocyclonic technology to pick up the mixture of metallic and non-metallic elements that make up the internal sludge in your radiator. It can be connected directly onto 22mm pipework and can be installed horizontally or vertically, allowing greater flexibility in positioning.


  • Ideal for areas with restricted space and access
  • Fast and easy to clean without having to dismantle your unit
  • Options of vertical or horizontal offer improved position flexibility
  • Doesn’t block or restrict flow of water

Are magnetic filters worth it?

We recognise that the answer to this question is a resounding yes. If you consider the level of damage and money that you’ve saved, getting a magnetic filter installed is definitely a no-brainer. Once you have it, you’ll be able to enjoy:

  • A clean heating system free of sludge and Iron Oxide deposits
  • Reductions on your annual energy bills
  • Extended lifespan on your boiler

This is just a short recap of the benefits available to you, but it’s clear to how you can introduce improvements to your property’s heating.

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