Our latest installation guide focuses on the TF1 Sigma Filter from Fernox, follow our step-by-step information to know all you can about correctly installing this product.

The TF1 Sigma Filter is the newest addition to the Fernox range of sealed in-line system filters. It has been designed without a lid so there is no need for replacement O-rings; not only saving time on-site but reducing the cost to service. 

The filter is cleaned within minutes by simply removing the magnet from the sheath and opening the drain valve to remove the dirt and sludge. 

Its simple design not only ensures mess-free cleaning but allows dosing using the Fernox Express range in 30 seconds. The TF1 Sigma Filter is available with either valves or slip socket connection.

According to the company, the TF1 Sigma Filter is compact, robust, and easy to install. It can be installed vertically, horizontally, or in any orientation in both flow directions, and positioned at an angle up to 45°.

Like its brass counterpart, the TF1 Omega Filter, the TF1 Sigma Filter is available in both 22mm and 28mm versions and uses a combination of unique Hydronic Particle Separation (HPS) technology and magnetic filtration to remove system debris quickly and effectively from a domestic heating system. 

  1. Unbox your brand new Fernox TF1 Sigma Filter, in this case a slip socket version.
  2. Switch off the pump and the boiler, and partially drain the system. Find a suitable length of pipework – ideally, this should be on the return to the boiler. This is so any debris from the system can be captured before it enters the boiler. 
  3. Mark out 70mm of pipework and then remove this with pipe cutters.
  4. Check the arrow on the TF1 Sigma Filter manifold and ensure it points in the direction of the flow – on return pipes, this tends to be upward on the vertical pipe into the boiler.
  5. Slide one end of the TF1 Sigma Filter unit onto one side of the pipe, and then slot the second end onto the other side – on the vertical pipe, the filter will be held in position by a ‘shelf’ within the manifold.
  6. Place one adjustable spanner into specified manifold area to hold the filter securely in place. Use a second spanner to tighten the compression nuts – the first spanner will prevent the pipe from bending and ensure the nuts are secured. Repeat on the other side. 
  7. Treat the system with an inhibitor, such as Fernox Protector F1, to protect against corrosion and limescale formation in the system. 
  8. Re-pressurise the system and start the boiler. Job done.