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1,567 reviews

Magnetic Filters: Are they Worth it?

Becky Mckay
By: Becky Mckay
Updated: 6th July 2022

Magnetic filter

The last thing you want is for your boiler to run less efficiently or, worse, stop working altogether. The rust and debris that builds up in your pipes over time can turn these scenarios into a reality.

That doesn't mean to say you have to just accept that this will happen, far from it. A magnetic filter can be installed which will collect the sludge and dirt before it builds up within your central heating system, so your boiler can continue to run as efficiently as ever.

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Why do I need a magnetic filter?

Magnetic filters, or boiler filters, are fitted to your boiler's pipework, extracting any debris from the water flowing through the pipes so that there isn't a build-up which can restrict the flow of water.

Fitting a magnetic filter to your boiler could bring many benefits to your home:

  • More efficient heating system
  • Lower energy bills
  • Reduced carbon footprint
  • Greatly reduced risk of needing expensive repairs
  • Longer boiler lifetime
  • Increased length of boiler warranty

What causes sludge to build-up?

As water passes through the metal pipes of your boiler, rust can form. Combine this rust with other dirt and debris, it eventually builds into a mud-like substance, otherwise known as 'sludge'. If this sludge isn't removed it can have a real impact on the day-to-day use of your heating system:

  • Excessive noise from the boiler and/or radiators
  • Radiators struggling to heat up
  • Cloudy water from the taps
  • Boiler regularly shutting down.
  • In the long term your boiler won't be running as efficiently which can cause energy bills to rise and, in the worst case scenario, the boiler may need to be replaced.

Best magnetic filters

When it comes to finding a magnetic filter for your boiler, there are lots of models to choose from so it can be tough to know where to start looking. To help you find the right boiler filter, we've compared some of the most popular models on the market.

Magnetic Filter Fernox TF1 Trappex Centramag Adey Magnaclean Professional3 Sense Filter Sentinel Eliminator Vortex
Size 22mm or 28mm 22mm 22mm 22mm
Potential Cost £75 – £170 £50 – £80 £80 – £120 £80 – £150
Warranty 2 years 2 years (10 years magnet warranty) 10 years

Fernox TF1

  • Removes magnetic and non-magnetic contaminants from the water
  • Contains contaminants safely within the filter
  • Fits onto vertical and horizontal pipework
  • Doesn't restrict the flow of water
  • Easy to clean

Trappex Centramag

  • Can be fitted onto vertical and horizontal pipework
  • Includes 5 non-magnetic dirt separators
  • Can be serviced quickly without the need to disassemble
  • Has a maximum working temperature of 130°C

Adey MagnaClean Professional3 Sense Filter

  • Ideal for larger heating systems
  • Fitted with rapid fit connectors which allows for faster servicing
  • 360° rotational valves mean it can be installed on horizontal or vertical pipework
  • An 'ultra-thin' sheath allows for greater magnetic capture

Find out more about ADEY Magnaclean Filters.

Sentinel Eliminator Vortex

  • 360° T-piece for easy installation
  • Can be flushed or wiped for simple cleaning
  • Fitted with a Vortex Core enhances debris retention and also ensures that the filter won't block

If you're planning to have a new boiler installed in the near future, then it's worth noting that some boiler manufacturers have their own magnetic filters. If you choose to add to your new boiler with one of their magnetic filters then the warranty period of the boiler could be extended.

  • Worcester Bosch System Filter
  • Alpha Cyclone Plus
  • Vaillant Boiler Protection Kit

Can I add a magnetic filter to my heating system?

Magnetic filters are most commonly added to a boiler during installation, they're not essential but the installer may recommend having one.

If you'd like to add a magnetic filter to your heating system but aren't looking to replace your boiler then you can still have one fitted to your existing system. However, depending on where your boiler is installed, it might not be practical. We highly recommend getting a quote from a Gas Safe engineer who will be able to let you know if the work is possible.

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Do magnetic filters need cleaning?

The sludge that the magnetic filter is clearing from the heating system needs to be removed from the filter itself every now and then. You can ask an engineer to do this during the annual service of your boiler.

What if I don't have a magnetic filter?

Without a magnetic filter preventing a build up of contaminants before a blockage occurs, your system might eventually require a powerflush. An engineer will be required to carry out a powerflush, which pumps chemicals through the pipes, boiler and radiators to remove sludge, rust and limescale. This isn't a quick job and the whole process can take between 6-10 hours.

In the worst case scenario, the system can get so damaged that the system might need replacing.

Is a magnetic filter worth it?

When having a new boiler installed, you want to know that you'll be able to rely on it to provide your home with heating and hot water for many years to come. This is where a magnetic filter can help.

As sludge and dirt build up in the pipes, your boiler will slowly lose efficiency which can then lead to your energy bills increasing. A boiler filter will capture all of the dirt and debris before the water is prevented from flowing through the system.

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Becky Mckay

About the author

Becky Mckay

Becky is one of our home heating and renewable energy experts and has a wealth of experience writing about the world of heating.

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