Electrolytic scale inhibitor for protecting hot water systems

Limescale build-up inside household appliances can cause them to run less effectively, increases the likelihood of premature breakdown and impairs the efficiency of heat transfer. The Sentinel SESI is a cost-effective scale inhibitor solution to help tackle limescale build up and could save up to £100 a year on typical energy bills.

Check the water in your area

Use our simple postcode checker to quickly find the hardness of the water in your area.

Check now

Key features

  • Protects against limescale encrustation
  • WRAS approved
  • 5 year guarantee
  • Performance proven by independent studies
  • Available in 15mm and 22mm
  • Recommended by the Compliance Guide to Part L1 of the Building Regulations

Available sizes

15mm SESI15
22mm SESI22

65% of the UK population is provided with hard water, which contains high levels of calcium and magnesium salts. These build up inside household appliances, causing them to run less effectively and increasing the likelihood of premature breakdown. By protecting against the build up of limescale, it could save up to £100 a year on typical energy bills, as scale also impairs the efficiency of heat transfer.

Sentinel SESI is an electrolytic scale inhibitor, a cost-effective solution to help tackle limescale build up. It provides a long term solution which requires no maintenance and protects the whole house without introducing any undesirable chemicals to drinking water. Sentinel SESI is easy to fit, WRAS-approved and comes with a 5 year guarantee.

The unit should be installed in the rising main of the municipal water supply, but after the water meter and primary filter units (if fitted), so that the whole property is protected. If the device is fitted to protect only a single appliance, there should be at least 3 metres of water pipe between the SESI unit and the appliance.

The unit must be installed in accordance with WRAS installation requirements.

 Sentinel SESI 15mm Version
Outer BodyCopper
Anode MaterialBespoke Zinc Alloy
Test Regulations(UK) WRAS Certification 0706038 
Connection15mm* Compression
Design Flow0-25l/min (1.5m 3/hr)
Length195mm
Width35mm (max)
Weight0.35kg

 

 Sentinel SESI 22mm Version
Outer BodyCopper
Anode MaterialBespoke Zinc Alloy
Test Regulations(UK) WRAS Certification 0706038 
Connection22mm** Compression
Design Flow0-37l/min (2.22m 3/hr)
Length190mm
Width35mm (max)
Weight0.40kg

*Removal of compression fittings converts unit to 1/2” BSP

**Removal of compression fittings converts unit to 3/4 BSP