Iron in a heating system is a silent killer of pumps – magnetite particles settle on the impeller, in the circulation pump chamber, and in the boiler heat exchanger. In this article, we show how a magnetic iron filter works and where to install a water iron filter in central-heating and domestic-hot-water systems. We write from the perspective of the Dambat team – the manufacturer of the IBO and IPRO brands – based on real products from our catalog.
Where iron comes from in a system and why it harms the pump
In a closed central-heating system, the main iron compounds are produced by corrosion of steel components. Magnetite circulates with the fluid until it settles in the narrowest restriction – usually in the gap between the impeller and the pump housing. A good filter removes iron compounds continuously, and the iron-removal process protects the pump against seizing. In domestic hot water, the problem has a different source: well water, groundwater, and mains water may be rich in iron. Such iron-containing water causes a rusty color, a metallic taste, and an unpleasant water odor – a sign that the water parameters need to be corrected and that iron removal from water is required. A high iron content reduces efficiency and increases water consumption, so if your system contains steel or you have your own water intake, you probably need a water iron filter.
How the IBO magnetic iron filter works
Our magnetic water iron filter combines hydrocyclone separation with magnetic capture. The operating principle of the iron filter is simple: the fluid enters tangentially and begins to swirl, heavier particles settle, and the magnetic core attracts magnetite. The iron filter's operation is based on two barriers – a magnetic field that captures iron ions and a mesh filter. This dual iron-filtering action makes iron-compound removal effective regardless of whether the sediment is magnetized.
Details from our catalog – the IBO magnetic filter series has consistent specifications that make selection easier:
- Filtration: ≥ 500 µm (stainless-steel mesh); in the IBF-04 model, even ≥ 100 µm
- Magnet strength: 9,000 Gauss
- Max. liquid temperature: 90°C
- Max. operating pressure: 8 bar (I-001/002/003 series) or 3 bar (IBF separators)
- Max. flow rate: 30, 70, or 100 l/min depending on the model
These are water iron filters that use a magnetic field – the simplest iron-removal technology to operate. The second family consists of media tanks – a different water iron-removal method described below.
Installing a water iron filter in a central-heating system – protection against ferrite deposits
In central heating, installing a water iron filter is intended to protect the circulation pump against ferrite deposits. Install the filter on the return line, just before the boiler and the pump, so that iron removal takes place before the sediment settles. A key advantage of our designs is their integrated shut-off valves: using a water iron filter simply involves closing both valves, opening the drain, and flushing the housing – without draining the entire system. This water iron-filter flushing takes a few minutes, and a flushed iron filter is immediately ready for operation again. A water-flushed iron filter does not require chemicals.
Match the diameter to the connection size (¾" or 1") and the flow rate. You can find central-heating models in the magnetic separators and iron filters collection: the IBO I-003 1" magnetic filter (100 l/min, 8 bar), the smaller I-003 ¾", and the IBO IBF-07 1" separator (70 l/min, housing 230 × 145 mm).
Installation in domestic hot water and utility water – water quality matters
In domestic hot water systems, install the filter or iron filter alongside the other water filters, before the inlet to the pump or boiler, so that iron-free water reaches the end devices. Combining a mechanical filter with a magnetic one provides effective water filtration for homes supplied by wells; dedicated iron-removal filters capture sediment before it enters the system. This is where utility water is used – washing machine, dishwasher, shower – and the goal is clean drinking water without deposits. A terminology note: although people say that an iron filter softens water, it actually removes iron compounds, while a water softener reduces water hardness. Water softening and iron removal are different processes – that is why we combine water treatment and softening in one line, in the proper sequence.
When manganese is also present in the water, we use a manganese-removal filter. Manganese-removal filters work similarly to iron-removal filters, but the media is selected for manganese; the two functions are often combined in a device with multifunctional media, which improves utility-water quality without multiplying the number of devices. An example of an inline product for utility water is the ¾" magnetic water treatment device with a scale reducer (10 bar, up to 120°C).
Magnetic filter or media tank? Two water-treatment technologies
In water-treatment technology, there are two product families. Classic water iron filters are pressure tanks filled with filter media; they carry out the water-treatment process by aerating the water and passing it through iron-removal media, which captures precipitated iron, while flushing regenerates the media. A magnetic filter is an inline device without filter media – lower water-treatment costs and no cartridge to replace. A tank is the better choice where a high iron content persists throughout the year, because magnetic removal of excess iron has its limits. Complete water iron-removal systems often combine both stages. The water iron filters available from us come in different sizes, so reliable water iron filters are a matter of choosing the right model, not the largest one.
Selecting a water iron filter – without oversizing
Proper water iron-filter selection starts with the numbers. Have the water tested – a water-quality analysis will show the iron concentration, manganese, water hardness, and pH, as well as any exceedance of iron standards. The second variable is flow: match the filter's maximum flow rate (30/70/100 l/min) to actual demand, coordinating it with the capacity of the submersible pump or surface pump and the capacity of the diaphragm tank. The third is the goal: in domestic hot water systems, we aim for high water quality, and improving water quality usually involves the sequence mechanical filter → iron/manganese-removal filter → optional water softening. You can set pump control using controllers and inverters.
Operation and maintenance
Even the best iron filter requires maintenance: close the valves, remove the cartridge, remove the sediment, and flush the housing. The frequency depends on the intensity of iron removal – from once a quarter in a heavily corroded central-heating system to once per season in clean mains water. If the rusty color returns despite servicing or the amount of iron in the sample increases, expand the water-treatment system with a media tank. Water contaminants also place stress on valves and the heat exchanger, so consistent removal of iron compounds extends the service life of the entire system – including the domestic-hot-water circulation pump and submersible pumps. We have collected the full range in the thermal comfort in your home collection. Using iron filters is an investment in a longer pump service life – choose a device based on the actual water parameters, and if you are unsure which water iron filter to choose, contact us.
