Fernox TF1 Compact 22mm Magnetic Inline Filter

In-Depth Look

The Fernox TF1 Compact is a physical filter for central heating system water. It is often fitted alongside a chemical inhibitor such as Fernox F1, so the system has both a filter and a water treatment.

How It Works

The TF1 Compact uses two methods at once. Hydrocyclonic action spins the system water so that heavier non-magnetic debris, such as rust flakes, scale and installation grit, drops out into the collection chamber. Neodymium magnets capture magnetite, the black iron oxide sludge that forms when steel radiators corrode inside. Magnetite is a common cause of blocked heat exchangers, sticking pumps and valve faults.

Size and Fitting

The body is smaller than a full-size filter, which helps where space is tight, such as under a wall-hung boiler or inside a kitchen cupboard. The kit includes 22mm valve connections for fitting to the pipework, and the filter can go in horizontal or vertical pipe runs. The body is glass-fibre reinforced nylon, rated to 3 bar and 100°C.

Servicing

Retailers describe the filter as designed to be cleaned without dismantling. The included isolation valves let the filter be isolated from the system for servicing. Follow the Fernox instructions for the cleaning steps, and check the filter at each boiler service.

Summary

The Fernox TF1 Compact is a magnetic and hydrocyclonic filter for 22mm central heating pipework. Fitted with an inhibitor, it helps keep sludge and debris out of the boiler, pump and valves.

How It Compares

The Fernox TF1 Compact is a magnetic filter for central heating pipework. It combines hydrocyclonic action with a neodymium magnet, so it collects magnetic debris and also catches non-magnetic debris from the circulating water. This listing is the 22mm version, and the valves and fittings are supplied with it. The body is a glass-fibre reinforced nylon plastic, and the maximum working pressure is 3 bar at a maximum temperature of 100 degrees C.

It is described as compact, for tight spaces. It fits horizontal or vertical pipework, and also pipework at about 45 degrees. It can be cleaned without taking the unit apart.

For a larger magnetic filter, see the Adey MagnaClean Professional 2 magnetic filter. The Fernox F3 central heating cleaner and the Fernox F1 central heating protector are treatments added to the system water. Our guide to flushing central heating and our guide to choosing central heating components give more background.

For the 22mm version, the valves and fittings are supplied with the filter, so it can be isolated from the rest of the system.

Common Questions

What does a magnetic filter do in a central heating system? It collects iron oxide sludge and other debris from the circulating water, so that the debris does not travel on to the boiler and pump. The magnet holds magnetic material, and the hydrocyclonic action also drops out debris that is not magnetic.

Where does a magnetic filter go? The usual advice is on the return pipe near the boiler. Check the instructions for the position that suits your pipework, and for the 22mm size, which is the one covered here.

How do I clean a magnetic filter? Switch the boiler off first. Then remove the magnet from its sheath as the instructions show, and flush the collected debris out through the drain valve. Because the unit is cleaned without taking it apart, you do not need to dismantle it. Follow the maker’s instructions for each step, because the order matters.

How often should it be cleaned? Follow the instructions or the advice of your installer. There is no single interval that suits every system.

What is the difference between a hydrocyclonic filter and a magnet-only filter? A magnet-only filter holds magnetic debris. Hydrocyclonic action also slows the water, so that debris which is not magnetic drops out of the flow. The TF1 Compact uses both.

Why do the maximum pressure and temperature matter? They are the limits the filter is built to work within. The TF1 Compact is rated to 3 bar and 100 degrees C, so check that your system operates within both figures before fitting it.

Heating work should be done by a competent, qualified installer if you are unsure. Follow the manufacturer’s instructions.