TF1 Sigma UB Filter

Warranty: 10 Year (s)

Composite under boiler system filter with a brass manifold designed for easy installation in small, restricted areas and with concealed pipework. This high-performance filter can be installed directly under the boiler or in restricted spaces due to the compact, versatile design. The TF1 Sigma UB Filter offers the ultimate in installer choice and provides high efficiency protection against the build-up of system debris.

  • A high capacity, compact design
  • Ideal for use in restricted spaces
  • Integrated three way valve with filter isolation and cleaning functionality
  • Durable and robust construction, made from a high-quality glass reinforced engineering polymer, and non-porous forged brass
  • Will not block or restrict flow
  • Can replace return valve if required
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Product Data Sheet
Product Overview

The TF1 Sigma UB Filter body is constructed from a high strength engineering grade 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 filter manifold is constructed from a premium grade, non-porous forged brass, allowing for direct connections onto the system, and a simple servicing procedure via the precision engineered manifold.
The TF1 Sigma UB Filter has been designed to ensure there is minimal pressure loss in addition to maintaining a high collection efficiency. The filter has been designed to capture a range of system contaminates, whilst also ensuring it cannot block, reduce flow through pipework or impact the performance of the heating system.
The TF1 Sigma UB Filter utilises a range of high-quality component parts that ensure the filter offers optimum performance. The three-way ball valve has been designed to allow users to easily operate by hand, whilst also providing a reliable serving procedure. The filter manifold includes a secure connection to the system and a robust service point allowing the filter to be drained and cleaned. The magnet is made using premium grade neodymium, enabling a high efficiency capture rate, as well as a robust filtration medium that will ensure a continued and consistent level of collection


Designed to be installed close to the wall, the filter can be easily fitted under boilers and in all other areas where space is limited. The TF1 Sigma UB Filter can be installed under a boiler or in tight and restricted areas. Ideally the filter should be fitted on the return to the boiler and should be installed horizontally. To enable the TF1 Sigma UB Filter to be connected to the boiler and/or return flow pipes, separate flexible/corrugated pipes and/or adapters may be required (not supplied).

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 – 40 L/min
Maximum Working Temperature – 100⁰C
Capture Rate – Up to 100% of system contaminates

Operating Principle
– Contaminated water enters the filter via the brass manifold, carrying 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.

The dynamic flow created within the filter means dirty water is transferred directly to the central magnet assembly. The high-powered neodymium magnet is designed to capture and retain large quantities system debris, protecting the boiler and helping to prevent breakdown and costly repairs.

The engineered flow path within the filter reduces magnet wash-off and improves the pressure loss across the filter assembly, meaning the filter can capture the maximum amount of debris, whilst causing no restriction to flow.

Water is directed to pass over the magnet sheath before exiting via the manifold. As a result, system debris cannot escape from the filter and is either trapped in the area of low flow, or captured by the powerful neodymium magnet, to allow clean water to exit the filter.

The filter utilises a precision engineered three-way valve, meaning any dirt collected within the filter can be quickly discharged via the drain valve by simply removing the magnet from the sheath, and turning the valve handle to engage the service function and open the drain valve, at which point system debris will be flushed from the filter and removed from the system. This procedure is shown in the cleaning guide

Physical Specification / Properties

Filter Body – Glass filled, engineering polymer
Manifold – Nickel plated brass
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.

Compatible Boilers:
  • Ideal Atlantic
  • Ideal Mini
  • Ideal Esprit
  • Ideal Exclusive
  • Vokera Vibe
  • Vokera Unica
  • Vokera 
  • Vokera Vision
Compatible Boilers With Adapter:
  • Glowworm Compact
  • Ideal Logic
  • Ideal Logic Plus
  • Ideal Logic ESP1
  • Vaillant ecoFIT Sustain Combi
  • Vaillant ecoFIT Sustain System
  • Vaillant ecoTEC Sustain Combi
  • Baxi 200 unless Easy Permanent Link is fitted 
  • Baxi 400 unless Easy Permanent Link is fitted
  • Baxi 600 unless Easy Permanent Link is fitted
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Single Unit Dimensions(Height x Width x Depth)
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Outer Carton Dimensions(Height x Width x Depth)
Outer Carton Barcode (ITF)
78 × 214 × 102 mm
172 x 506 x 232 mm
Dimensions Diagram
TF1 Sigma UB Filter