TF1 Sigma Filter


A high-performance, precision-engineered in-line system filter, the TF1 Sigma Filter utilises a sealed, lidless design for increased reliability and strength. Ideal for use in restricted spaces due to its capability of being positioned in multiple orientations up to 45⁰.
This simple to install, composite plastic filter fits onto vertical and horizontal pipework, and works by allowing Hydronic Particle Separation (HPS) action to deliver contaminants to the unit’s powerful magnet assembly for safe removal.

  • Pressure tested, innovative sealed unit design to maximise reliability and promote fast, easy cleaning via the drain valve
  • Unique action, capturing a range of magnetic and non-magnetic debris through HPS technology
  • Durable and robust construction, made from a high quality glass reinforced engineering polymer with brass on plastic manifold
  • Convenient, mess-free and quick dosing via the drain valve – less time spent on-site when servicing the system
  • Easy to install – fits on horizontal and vertical pipework orientation
  • Will not block or restrict flow
Available Versions
Product CodeFit Type and SizeProduct Data Sheet (PDF)
Fit Type: With Valves, Metric Fitting Size (mm): 22mm
Fit Type: Slip Socket, Metric Fitting Size (mm): 22mm
Fit Type: With Valves, Metric Fitting Size (mm): 28mm
Product Overview

The TF1 Sigma Filter is constructed from a high strength engineering polymer, suitable for heating and cooling system applications. The glass reinforced polymer has good hydrolysis resistance, as well as high resistance to strain and abrasion. The polymer is compatible with glycols and additives used in central heating systems.

The TF1 Sigma Filter has been designed to ensure there is minimal pressure loss in addition to maintaining a high collection efficiency. The internal HPS, magnet assembly and area of low flow have all been engineered to allow the filter to capture a range of system contaminates, whilst not impacting the rest of the heating system.

The TF1 Sigma Filter utilises a range of high-quality component parts that ensure the filter offers optimum performance. The magnet is manufactured using a premium grade of neodymium, enabling a high efficiency capture rate, as well as a robust filtration medium that will ensure a continued and consistent level of collection.


The TF1 Sigma Filter can be installed on vertical or horizontal pipework, in accordance with the flow direction indicated by the arrow on the manifold. Ideally the TF1 Sigma Filter should be fitted on the return to the boiler and can be installed at up to 45⁰ from the vertical position if space or head height is restricted.

The TF1 Sigma Filter is designed to protect the boiler from the damaging effects of circulating corrosion debris, which has collected in the system as a result of a chemical reaction when water comes into contact with mixed metals used within a heating and cooling system. Treating the system with a quality inhibitor product from the Fernox Protector range will prevent the formation of sludge and scale long term in accordance with regulations and best practice.


Suitable Fluids:
Inhibited Glycol Solutions
Fernox Chemical Range / System Additives
Maximum Percentage of Glycol – 50%

Maximum Working Pressure – 5 bar
Maximum flow rate – 50 L/min
Maximum Working Temperature – 100⁰C
Capture Rate – Up to 100% of system contaminates

Operating Principle – Contaminated water enters the filter via the manifold, carrying a variety of system debris and particulate matter held in suspension. This debris, including ferrous impurities such as Magnetite, moves through the manifold and into the main body of the filter.
Water is forced down towards the bottom of the filter due to the engineered flow characteristics created within the filter by the Hydronic Particle Separator (HPS). The HPS action helps to disrupt any dirt particles held in suspension by the water, as well as direct these particles towards an engineered area of low flow at the base of the filter.
The dynamic flow of the water within the filter also allows ferrous impurities to be captured by the high-powered magnet assembly.
To exit the filter, water must pass over the magnet sheath and around the HPS, then out of the manifold. In this way, system debris has difficulty escaping the unit, and is either trapped in the area of low flow, or captured by the powerful magnet, meaning clean water exits the filter.
Any dirt collected within the filter can then be discharged by removing the magnet from the sheath and opening the drain valve. This procedure is shown in the cleaning guide and does not require system shutdown or the filter to be disassembled.

Physical Specification / Properties

Filter Body – Glass filled, engineering polymer
Manifold – Nickel plated brass and glassed filled engineering polymer
Drain Valve – Nickel plated brass
Circlip – Stainless Steel
Seals & Washers – EPDM

Package, Handling & Safety

As with all magnetic products, if you have an implanted cardiac device extra caution should always be taken when handling any magnetic filter.
Individually packaged, with instructions included. No special storage requirements.

Product CodeFit Type and SizeSingle Unit BarcodeSingle Unit Box Dimensions
(Depth x Width x Height)
Outer Carton Barcode (ITF)Outer Carton Box Dimensions
(Depth x Width x Height)
Fit Type: With Valves, Metric Fitting Size (mm): 22mm
180 x 255 x 115 mm
241 x 362 x 268 mm
Fit Type: Slip Socket, Metric Fitting Size (mm): 22mm
180 x 255 x 115 mm
241 x 362 x 268 mm
Fit Type: With Valves, Metric Fitting Size (mm): 28mm
179 x 346 x 112 mm
241 x 178 x 352 mm
TF1 Sigma – Precision Engineered Filter
How does Fernox Protector F1 work