Description
This is a compact in-line magnetic filter intended to protect domestic combi and system boilers in small properties where space is at a premium. It combines a strong neodymium magnet with a secondary strainer to trap iron oxide and other debris circulating in heating water so the boiler heat exchanger, pump and valves see less abrasive wear and sludge-related restriction.
Physically the unit is designed for 22mm domestic pipework and installs in series with the flow. The body is a high-strength polymer and the seals are made from high-temperature EPDM; the unit is supplied with 22mm brass compression fittings. Servicing is straightforward: a neodymium magnet captures fine magnetic particles around the central shaft while a mechanical strainer collects larger non-magnetic debris, and a low-level drain plug lets you clear collected material without dismantling the whole assembly.
Key specifications
- Model: MFILT Mini Magnetic Filter (MFILT01)
- Connections: 22mm (brass compression fittings supplied)
- Magnet: neodymium, rated at 9,000 gauss
- Body material: nylon / PA66-GF30%
- Seals: high-temperature EPDM
- Weight: 636 g
- Service features: low-level drain plug; triple-sealed isolating valves
- Category: Central Heating Products
- Typical retail price (supplied record): 36.50 GBP
How it works and what it protects
The filter uses a two-stage approach. A powerful neodymium magnet provides a focal point for ferrous particles — rust and fine iron filings — drawing them out of the circulating water and holding them against the magnet surface. Around the magnet sits a mechanical strainer that intercepts larger particles and non-magnetic debris such as mineral grit. That combination reduces the amount of abrasive material reaching sensitive components inside the boiler.
In practice this means the device helps to prevent common problems that shorten component life or reduce efficiency: pump bearing wear, partial blockage of heat-exchange surfaces and valve sticking. Cleaner water also helps maintain heat transfer efficiency across the system, so the manufacturer statement that a well-maintained system can see modest energy savings when fitted with effective filtration is credible in principle — though actual savings depend on the starting condition of the system and how comprehensively other maintenance tasks (flushing, inhibitor dosing) are carried out.
Installation, sizing and where it suits best
This filter is aimed at compact heating installations such as flats, small bungalows or apartment boilers where a full-size magnetic filter might not fit. It is made for 22mm pipework and is supplied with 22mm brass compression fittings, so it is straightforward to fit into typical UK domestic circuits where that pipe size is used.
Because of its compact form it is most appropriate where space is constrained or where the heating circuit carries a relatively low volume of water. For larger systems, systems with high sludge loads, or where the pipework is a different size, installers often prefer a larger in-line or full-flow magnetic filter with greater collection capacity and an accessible collection chamber.
Routine installation notes: fit the unit in the return to the boiler where flow is lowest (this is standard practice for magnetic filters), ensure the isolating valves are used to isolate during servicing, and use the low-level drain to remove trapped debris into a suitable container. As with any work on a gas boiler or associated pipework in the UK, the job should be carried out or signed off by a competent heating engineer (Gas Safe registered if the work affects gas appliances).
Servicing and everyday use
Servicing is designed to be low-effort: open the isolating valves, drain via the low-level plug and wipe the magnet and strainer as needed. The triple-sealed isolating valves make this process cleaner and reduce the risk of system water loss during maintenance. How often you need to service it depends on the system: newly commissioned or heavily fouled systems will require more frequent attention than a well-treated, recently flushed heating loop.
Remember that a compact filter holds a limited volume of debris. If you find it needs clearing very frequently that is a sign the system needs a full chemical flush and appropriate inhibitor dosing rather than repeated filter cleaning alone.
Practical advantages and limitations
- Advantages: space-saving, relatively inexpensive, easy to fit to standard 22mm pipework, combines magnet and strainer for broader protection than a magnet alone.
- Limitations: designed for 22mm only (no indication of other sizes supplied), smaller debris capacity than larger domestic filters, no micron rating for the strainer given in the supplied record.
Overall, this MFILT Mini Magnetic Filter is a pragmatic option where you need reliable, low-cost boiler protection in a restricted space. It does the basic work of intercepting magnetic debris and provides a mechanical barrier for larger particles; however, it is a complementary product — not a substitute for proper system commissioning, periodic flushing or chemical treatment when those are required.
