The Best Magnetic Filters For All Central Heating Systems

Choose from our handpicked selection of central heating filters to ensure your system's efficient performance and save yourself from costly repairs.
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Written & Tested By: Richard Morgan | Updated:
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best magnetic filter for central heating
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The purpose of a central heating magnetic filter is to capture any contaminants before they reach the boiler. As you can imagine, this comes with many benefits because it helps to keep the system clean, which will extend the life of the boiler and ensure it runs efficiently.

In terms of the installation, they are fitted to the pipe that returns water to the boiler (as shown in the photo of our MagnaClean filter above) and the magnets work by attracting contaminants before they are passed back to the boiler. As you’ll see from our testing and experience using these filters, they certainly capture a lot of contaminants over time.

To help you choose the right magnetic filter for your central heating system, our hand-picked selection features top-performing models chosen through our first-hand experience using and seeing the results from multiple types, testing and the latest research.

Our Top Picks At A Glance:

Magnaclean System Cleaner
Best Overall: Magnaclean Professional 2 Magnetic Filter
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Fernox TF1 Central Heating Magnetic Filter
Best Versatile: Fernox TF1 Central Heating Magnetic Filter
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Boilermag Domestic Heating System Filter
Best Budget: Boilermag Domestic Heating System Filter
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Worcester Greenstar Central Heating System Filter
Best Quality: Worcester Greenstar Central Heating System Filter
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Altecnic Dirtmag IQ Magnetic Sludge Filter
Best All-Rounder: Altecnic Dirtmag IQ Magnetic Sludge Filter
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Boiler-m8 Defender Magnetic Filter
Best Budget Runner-Up: Boiler-m8 Defender Magnetic Filter
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How The DIY Works Team Tests & Rates Central Heating Filters

As we own a number of properties (Airbnb’s and rentals), it means that we also have several boilers to maintain. Therefore, over the years, we’ve had various central heating filters installed during new boiler installations as well as servicing where applicable. In terms of installing them, we left that to the professional heating engineers.

However, when installing the filters, we always ask for their input in terms of the installation process. During the testing of the filter’s effectiveness, when the boiler is being serviced, we also ask to see the containments that they’ve captured.

As you can see in the images below from a recent boiler service, the TF1 filter (as recommended in our roundup) captured a lot of debris during a single year of use in one of our rental properties.

central heating magnetic filter

Richard Morgan/DIY Works
magnetic central heating filter

Richard Morgan/DIY Works

To keep up our commitment to reviewing and testing the latest central heating filters, we are continually testing the latest offerings from top brands in the UK. This means that we are upgrading our current central heating filters during the boiler’s annual servicing when we spot that brands have released new and improved filters.

best central heating sludge remover

Richard Morgan/DIY Works
best central heating filter

Richard Morgan/DIY Works

As well as our testing and experience with a range of central heating filters, we also based our recommendations on the latest research and a number of factors. Some of the factors that we took into consideration included the effectiveness, ease of installation, supplied hardware, certification, design, warranty and value for the money.

The Best Central Heating Filters

At DIY Works, our content is 100% independent and we would never recommend a product that we wouldn't use ourselves (read our editorial standards and how we test products).

1. Best Overall: Magnaclean Professional 2 Magnetic Filter

(How We Review →)

The MagnaClean Professional 2 is a popular central heating filter that has a compact design for tight installation spaces. The brand claim that due to its versatile design, you can install the system cleaner in just 2 minutes.

Included in the box are the filter, isolate valve fitting, lid and valve spanner, installation guide, warranty card and labels.

Pros
  • Low profile drain valve
    •
  • Twin reverse flow for maximum debris capture
    •
  • In-line installation takes just 2 minutes
    •
  • Suitable for all boiler types
    •
  • Available with a 22 or 28 mm diameter
    •
  • Durable stainless steel housing
Cons
  • Relatively expensive when compared to the alternatives

To conclude, the MagnaClean Professional 2 is the complete package and by far the most popular choice.

According to the brand, it’ll provide impressive results by capturing sludge and large iron particles for years to come and since having ours fitted, we’ve certainly had no complaints.

It’s worth pointing out that although the brand offers a Professional 3 model, for most homeowners it isn’t worth paying the extra because the only difference is the inclusion of WiFi, which allows for remote viewing of the heating system.

2. Best Versatile: Fernox TF1 Central Heating Magnetic Filter

(How We Review →)

Another popular magnetic filter for central heating systems is the Fernox TF1. The brand state that it’s a “revolutionary” hydro-cyclonic and magnetic inline filter, which uses a unique action to remove all contaminants.

Unlike many of the alternatives, this magnetic filter doesn’t need to be removed or disassembled for cleaning. This means that it can take just seconds to clean the filter for maximum cleaning power each and every time.

Pros
  • Removes both magnetic and non-magnetic debris
    •
  • Fits vertical or horizontal pipework
    •
  • Easily accessible dosing point
    •
  • Cleans in seconds without the need to remove it
    •
  • Includes valve fittings, rubber washers, instructions and labels
Cons
  • Only available with a 22mm diameter

Overall, the Fernox TF1 is a highly-rated magnetic filter that’s suitable for the majority of heating systems. It also has the benefit of being able to be installed either horizontally or vertically, which may be a requirement for certain installs.

3. Best Budget: Boilermag Domestic Heating System Filter

(How We Review →)

If you are on a tight budget, the Boilermag Domestic is a more affordable option to consider that’s able to extract both magnetic and non-magnetic debris. As with the Fernox TF1 above, this central heating filter can be installed at any angle, which makes the installation of the pipework far simpler.

Compared to similarly priced filters, this magnetic filter comes with an impressive three-year warranty for peace of mind. In terms of what’s included, the box contains the filter, brass isolation valves, valve seats, bowl spanner, pipe cut template, magnetic core remover, security seals and labels.

Pros
  • Backed by a three year warranty
    •
  • Fits any angle pipework
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  • No block design
    •
  • Extracts both magnetic and non-magnetic debris
    •
  • Everything you need is in the box
Cons
  • Build quality isn't as well-made as the premium alternatives

To conclude, the Boilermag Domestic is the complete central heating filter package that meets all the latest UK standards. Considering its budget price tag, you really can’t go wrong and it certainly won’t disappoint.

4. Best Quality: Worcester Greenstar Central Heating System Filter

(How We Review →)

Worcester is one of the best boiler brands in the UK but they are also known for their premium price tags and this filter is no different because it’s by far the most expensive in this article. However, unlike any of the alternative central heating filters, this filter is also available in a 28mm pipe diameter.

In order to improve the ease of servicing the filter, the construction has a one-way valve for adding system chemicals as well as a completely detachable body.

Pros
  • Available as a 22 or 28 mm diameter
    •
  • Meets the GASTEC standards
    •
  • Captures magnetic and non-magnetic contaminants
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  • Easy access drainage point
    •
  • Detachable body for easy servicing
    •
  • Can be installed under or over the boiler
    •
  • Includes a 12 month warranty
Cons
  • Most expensive within our roundup

Although expensive, the Worcester Greenstar is a highly rated central heating filter that’ll do a great job at increasing the efficiency of your system. It also has a well-thought out design that helps to improve the ease of servicing and certain aspects such as the design make it worth spending the extra.

5. Best All-Rounder: Altecnic Dirtmag IQ Magnetic Sludge Filter

(How We Review →)

The Altecnic Dirtmag IQ is another affordable magnetic filter that’s able to capture both magnetic and non-magnetic dirt. However, compared to similarly priced filters, this model has far superior build quality with a high-density polyethene internal filter and neodymium magnets.

Pros
  • Triple separation action
    •
  • Fits vertical or horizontal pipework
    •
  • Chamber is manufactured from glass fibre polyamide 66
    •
  • Built-in air valve that vents out any air in the system
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  • Servicing doesn’t require isolation
    •
  • Includes a two year guarantee
Cons
  • Only available as a 22mm

Overall, the Altecnic Dirtmag IQ is an excellent all-round option that combines build quality with value for the money. It also has unique features such as a built-in air valve, triple separation and other features that make it stand out from the crowd.

6. Best Budget Runner-Up: Boiler-m8 Defender Magnetic Filter

(How We Review →)

The Boiler-m8 Defender is a cheap, guaranteed replacement magnetic filter that’s CE-approved and comes with a two-year extended warranty. Although it’s the cheapest within our roundup, this particular model is constructed of premium stainless steel filtration and includes high-powered magnets for capturing debris.

Pros
  • Available with a 22 or 28 mm diameter
    •
  • Constructed of high powered magnets and a stainless steel filtration
    •
  • Removes both magnetic and non-magnetic debris
    •
  • Easy to service and maintain
    •
  • Manual air vent but available with an automatic
    •
  • Includes a 2 year warranty
    •
  • CE approved
Cons
  • Supplied instructions are very basic (may require additional research to install it)

If you require a cheap magnetic filter for your central heating system that’ll actually perform to a high standard, the boiler-m8 Defender is the best option. It’s built to a much higher standard to which you would expect from the premium alternatives and it’s also backed by a two-year warranty for peace of mind too.

Conclusion

If you are installing a new boiler in your home, a magnetic filter is an optional component that’ll pay for itself in the long run. As mentioned by Viessmann, your boiler warranty may even be affected if a filter isn’t used.

All of our recommendations are suited to a range of budgets and will instantly help capture contaminants in the system. However, to avoid disappointment, we recommend that you buy from reputable brands.

If you require further information regarding our central heating filter recommendations, feel free to get in touch and we will try to provide our assistance where possible.

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