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?

If your boiler breaks down due to sludge in the system, the repair work is not covered under your warranty and can lead to expensive repair bills as a result.

Why should I have a filter fitted?

Many boiler breakdowns occur due to sludge in the heating system. A magnetic filter is an effective way of preventing this sludge from accumulating, and may prevent costly breakdowns at a later stage.

Why are my radiators cold?

If you notice that your radiators are cold to the touch, you may have air or sludge trapped inside the system. These can be simple to resolve, but if you’re concerned, contact a heating engineer to help.

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

Issues with your radiator temperature, leaks from your boiler, and unusual sounds from within your system are all indicators that there is a buildup of sludge.

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

Issues with your radiator temperature, leaks from your boiler, and unusual sounds from within your system are all indicators that there is a buildup of sludge.

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