2. Why should I get a magnetic filter fitted

Why should I have a filter fitted?

Many boiler breakdowns that occur are due to sludge in the heating system.


This ‘sludge’ (which is also known as magnetite) is caused by fragments of rust and other debris in the pipes that accumulates over time and, if left, can cause cold patches on your radiators, make your boiler work harder to heat your home and also can block or damage the components inside your boiler.


A magnetic filter will attract the magnetic debris in the system water before it enters your boiler, which has many benefits:


  • It can extend the life of your boiler and central heating system
  • It reduces the risk of your boiler breaking down and having to pay for costly callouts
  • It reduces the expense of replacement parts
  • It can reduce your energy bills by up to £80
  • It can reduce your carbon emissions by 7%
  • It can increase the heat from your radiators by up to 47%


It is worth noting that our boiler warranties do not cover damage to the boiler that is caused by sludge in the system.

What is central heating sludge?

Sludge or magnetite if left to build up, can damage the boiler and the heating system. Find out everything you need to know about Sludge here.

Do I have to have a magnetic boiler filter installed?

Fitting a filter is considered best practice when installing a new boiler.

Related FAQs

Why should I get the water in my central heating system cleaned?

It’s important to have the water in your central heating system cleaned regularly to prevent sludge buildup, which can lead to blocked pipes and ultimately, cause breakdowns. Repairs needed as a result of sludge are not covered by Baxi warranties.  

Read more

Why should I have a filter fitted?

Boilers tend to break down as a result of sludge building up in the system. A magnetic filter captures these particles and prevents them from entering your boiler system, extending the life of your appliance and reducing the risk of a breakdown.

Read more

Why are my radiators cold?

Cold radiators are usually a consequence of air being trapped inside the radiator. Simply bleed the radiator and the problem should be resolved. Sludge buildup can also cause differences in the top and bottom of your radiator and impact its efficiency. 

Read more

How do I know if I've got sludge in my central heating system?

If you notice your radiators are hot at the top but cold at the bottom, or need to bleed your radiators more often, then you may have sludge built up in your system. 

Read more

Does my boiler filter need cleaning?

Your filter should be cleaned during your boiler’s annual service. This will prevent sludge building up in your system. Some filters come with an app that can warn you when they filter needs to be cleaned, so that you can arrange for your installer to visit before it gets too full.

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