CALEFFI magnetic filter for under-boiler installation XS® model 545900

CALEFFI magnetic filter XS® model 545900 is a compact under-boiler filter designed to protect central heating systems by capturing ferrous particles and retaining sludge. Installed on the return pipework near the boiler, the unit combines a strong magnetic core that attracts iron debris with a mechanical filter body that traps non‑magnetic particulates. The result is reduced wear on circulating pumps, heat exchangers and other hydraulic components, and improved reliability of residential and light commercial heating installations.

Advantages

The magnetic core efficiently attracts and holds iron filings and rust particles, helping to prevent blockages and erosion in sensitive components. The filter body retains sludge and coarse debris, easing routine maintenance by concentrating contaminants in a removable housing. Designed for under-boiler installation, the product has a compact footprint and straightforward connection points for integration with existing return lines. Materials and construction are selected for compatibility with typical heating system fluids and temperatures.

Suitable for

• Residential central heating systems
• Light commercial heating installations
• Boiler return lines where protection of pumps and heat exchangers is required
• Systems prone to ferrous contamination or visible rust

Key specifications

• Installation position: under‑boiler, on return pipework
• Filtration principle: magnetic separation combined with mechanical particle retention
• Target contaminants: ferrous particles, rust, sludge and coarse particulates
• Compatibility: designed for closed central heating circuits using standard heating fluids
• Construction: removable filter housing with magnetic core for maintenance and cleaning

How to use

Mount the magnetic filter on the return line close to the boiler according to system piping layout and local regulations. Isolate the section of piping, drain the system pressure as required and connect the unit using the appropriate fittings. After installation, system commissioning should include flushing to remove loose debris, followed by refilling and venting. Periodically isolate the filter, remove the housing and clean the magnetic core and filter surfaces to restore full performance. Follow the boiler and system manufacturer's instructions when performing maintenance.

Usage recommendations

For best results, check the filter during initial commissioning and then inspect at regular maintenance intervals; frequency depends on system condition and age. When cleaning, avoid aggressive mechanical impacts on the magnetic core and ensure all seals are properly reinstalled to prevent leaks. Combine the magnetic filter with good water treatment and system flushing practices to minimise future contamination and extend component life.