If you’ve had a new boiler installed in the last few years — or you’re thinking about it — chances are someone’s mentioned a “magnetic filter.” But what actually is it? What does it do? And do you really need one?

Here’s what we tell homeowners across Exeter who want to protect their heating system for the long haul — without wasting money on unnecessary extras.

What Is a Magnetic Filter?

A magnetic filter is a small unit that gets fitted to your central heating system’s pipework — usually near the boiler.
Its job is to catch rust, sludge, and debris before it circulates around your system.

Think of it like a water filter — but for metal particles.

Over time, your radiators and pipework naturally corrode. This creates a fine sludge (especially in older systems) that can:

• Block pipes

• Cause cold spots in radiators

• Damage your boiler’s internal parts

• Reduce system efficiency

The filter uses a powerful magnet to trap that sludge and stop it circulating — keeping your system cleaner and your boiler safer.

Do You Actually Need One?

In most cases — yes, it’s well worth it.

We’ve seen too many Exeter homes where boiler issues or cold radiators were caused by years of untreated sludge build-up.
Adding a magnetic filter is one of the cheapest and easiest ways to reduce future issues — especially after a power flush or new installation.

It’s particularly useful if:

• You’re fitting a new boiler to old pipework

• Your system hasn’t been flushed in a while

• You want to extend your boiler warranty (many manufacturers require one)

What Does It Cost?

Fitting a magnetic filter usually costs £120–£250 including parts and labour, depending on the brand and system layout.

Most of the time, we install them as part of a boiler upgrade — and can include it in the quote.

Some of the most common brands we fit:

• Adey MagnaClean

• Fernox TF1

• Spirotech MB3

We’ll recommend what’s right for your system — not just what’s trendy.

Do They Need Maintenance?

A good filter will work away quietly — but yes, they do need occasional cleaning.

At EPM, we check and clean them during your annual boiler service, making sure they’re still doing their job properly.
We also top up your system with inhibitor fluid to help slow down future rust build-up.

Final Thought from EPM

Magnetic filters aren’t exciting — but they are smart.
For a relatively small cost, you can protect a boiler worth thousands and keep your heating running better for longer.

If you’re unsure whether your system already has one — or you’re not sure it’s working — give us a ring. We’ll take a look and give you honest advice, no pressure.