Dirt separator Termojet DN25 (1") 110°C/10bar TJ-CD-DN25

TJ-CD-DN25 — DN25 dirt separator with a removable magnetic ring. The gravity chamber captures solid particles of sludge, rust, and sand, while the powerful magnetic ring attracts magnetite — the black ferrous deposit that gravity does not retain. Installed on the return pipe before the boiler, pump, or heat pump heat exchanger.

Technical Specifications

How It Works

The heat carrier slows down in the expanded housing chamber. Solid particles — rust, sand, sludge — are heavier than water: they settle to the bottom of the chamber under gravity. The magnetic ring, mounted around the housing, creates a magnetic field inside the chamber and attracts magnetite particles (Fe₃O₄) — the black ferrous oxide from corrosion of steel radiators and pipes. Magnetite «sticks» to the chamber walls in the magnet's zone of action. The accumulated sediment is drained through the bottom drain valve, without stopping the system. To clean the magnetic ring: remove it, wipe or rinse — the black deposits come off easily.

Applications

• Heat pump system. Magnetite accumulates in the narrow channels of the HP plate heat exchanger and gradually reduces its efficiency — up to complete failure. Only magnetic separation effectively protects the heat exchanger from this type of contamination. More about protecting heat pump systems at tjheatpump.com.ua.
• Gas or solid fuel boiler. DN25 covers systems up to 25–30 kW. The separator intercepts sludge and magnetite before the boiler inlet.
• System with steel radiators and pipes. Steel corrosion inevitably produces magnetite — without a magnetic separator it circulates in the system and accumulates in the narrowest points.
• After installation or flushing. Contaminants stirred up during system filling collect in the chamber during the first months of operation.

Advantages

• Removable magnetic ring — full magnetic separation without disassembling the housing: remove the ring, wipe, reinstall.
• Dual separation: gravity + magnet — retains both non-magnetic and magnetic particles.
• Dirt drainage without stopping the system — drain valve opens under pressure.
• Compact housing H145 mm — fits even in tight installation conditions.

Heat Pump and Magnetite

Heat pump systems are particularly vulnerable to magnetite. A standard dirt separator without a magnet does not retain this type of contamination — magnetite passes through the gravity chamber and settles in the HP plate heat exchanger. TJ-CD-DN25 with a removable magnetic ring effectively captures magnetite and protects the heat exchanger from costly blockage. Install on the return pipe before the HP heat exchanger. More about solutions for heat pumps at tjheatpump.com.ua.

Related Products

If the system also has an air problem — consider the air and dirt separator DN25 (2-in-1). For purchasing or replacing the removable ring separately — TJ-MAG magnet. All models in the Termojet separator catalog.

Frequently Asked Questions

Is a magnetic separator needed if the system has plastic pipes?
Even with plastic pipes, the system usually has steel radiators or an expansion tank. Corrosion of their steel surfaces produces magnetite. If all radiators are aluminium or stainless steel, and the expansion tank is also not steel — magnetite is unlikely. In all other cases, a magnetic separator is recommended.

How do I know when it's time to clean the magnetic ring?
Remove the ring and inspect it. If there is a black deposit on the surface — that is magnetite, and the ring needs to be wiped clean. During the first year of system operation (especially a new one), inspection every 3–4 months is recommended; later — once a year during maintenance.