A magnetic filter is one of the most valuable additions to any central heating system. If you don't have one, your heat exchanger is gradually accumulating damaging iron oxide particles right now.
What it does
Central heating systems corrode slowly from the inside. Iron oxide particles (rust) circulate with the water and accumulate on heat exchangers, causing reduced efficiency and eventual failure. A magnetic filter — using a powerful permanent magnet — captures these particles before they reach the boiler, collecting them safely where they're cleaned out during annual servicing.
The top brands
Adey MagnaClean: The UK market leader. The MagnaClean Professional 2 is our standard fitment. Fernox TF1: Strong alternative, particularly popular with system boilers. Both perform equally well in practice.
Is it required for my warranty?
Yes, for most major brands. Worcester Bosch, Vaillant, Baxi, and Ideal all state that sludge-related damage is excluded from warranty unless a magnetic filter was fitted. Heat exchanger replacement costs £300–£600 — the filter pays for itself the first time it prevents a warranty exclusion.
Do I need one if my system is clean?
Yes — all steel systems generate iron oxide over time. The filter prevents accumulation rather than just treating existing sludge. Best fitted on installation day of a new boiler. We include one as standard in every installation.