X100 Inhibitor X200 Noise Reducer X300 System Cleaner X400 System Restorer X500 Inhibited Antifreeze X700 Sanitiser and Biocide X800 Jetflo Ultimate Cleaner X900 Filter Aid Deposit Remover Leak Sealer Seal X Joint & Leak Sealer

X100 Inhibitor

Key Features
TripleTech™ Technology
Using X100
Safety Information

A general purpose treatment for total protection against scale and corrosion in all types of indirect central heating systems, including those containing aluminium. Will extend the life of the system, and ensure maximum efficiency and minimum fuel usage. Once added, Sentinel X100 Inhibitor never needs to be replaced unless the system is drained down. 

A number of X100 Inhibitor products are recommended by the Energy Saving Trust Recommended scheme.

X100 1L EST CompBuildcert-DWTA

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  • Heavy duty inhibitor
  • Enhanced scale & corrosion protection
  • For all system metals
  • pH neutral formulation - easy to handle
  • Ensures optimum boiler efficiency
  • Prevents boiler noise
  • Prevents pin-holing
  • Helps prevent the formation of hydrogen gas
  • A simple test kit is available to check levels
  • Harmless to the environment, completely non-toxic and biodegradable
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TripleTech™ Technology

X100 Inhibitor contains TripleTech™ Anti Corrosion Technology, a unique formula which has three different kinds of heavy duty specialist corrosion inhibitors, each of which target a specific metal type for unrivalled performance in a multi metal system.
TripleTech™ Anti Corrosion Technology has been formulated to protect against corrosion, scale, boiler noise and hydrogen gassing in all types of indirect heating systems.
The technology helps our products to outperform our closest competitors.

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Will Sentinel X100 protect my system if it is filled with softened water? 

Softened water, particularly those from household softeners not conforming to BS EN 14743, is not suitable for filling a domestic central heating system unless the water is treated with a high quality corrosion inhibitor. Unlike many other products on the market, Sentinel X100 has been especially designed to cope with all types of supply water, even softened water and affords complete protection.  

How long does Sentinel X100 last in the system?

Once the correct amount of Sentinel X100 has been added, it remains in the system indefinitely, providing ongoing protection. Depletion only occurs by dilution, e.g. when the system is topped up after removing, emptying and then re-connecting radiators during house decorating. It is necessary to check the concentration of Sentinel X100 using the Sentinel X100 Test Kit after replacement of system components (boiler, radiators etc) and replenished as necessary.  

Is Sentinel X100 compatible with other brands of treatment products?

The effects on system protection and function of system components cannot be predicted when adding Sentinel X100 to a system already containing other chemical inhibitors. Therefore, it is not recommended to mix Sentinel X100 with other inhibitor products.  

Can I use Sentinel X100 if I have aluminium components in my system?

Yes! Sentinel X100 has been specially developed to protect multi-metal systems, including those comprising aluminium components. Sentinel X100 protects aluminium by ensuring and maintaining neutral pH conditions.  

My water pH level is about 8.0 - will the Sentinel X100 increase this?

No. Sentinel X100 contains what is known as a pH "buffer". These ingredients in the formulation are designed to actually control the pH level in the water at neutral (approx. pH 7.0), even if the pH level of the incoming water is less than 6.5 or more than pH 8.0.  

What dosage should I use?

1 litre of Sentinel X100 is sufficient to treat a typical domestic system of up to 10 radiators.Larger systems should be dosed with 2 litres.  

Is there a Safety Data Sheet or a COSHH Data Sheet?

Sentinel X100 is non hazardous and zero COSHH rated. Both the Safety Data Sheet and the COSHH Data Sheet are available upon request.  

Can I use Sentinel X100 in a Primatic Cylinder?

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Sentinel X100 is suitable for use in all waters, both hard and soft. The formulation is completely non-toxic. 

For best results, systems should be cleansed and flushed in accordance with BS7593:2006 new systems and those up to 6 months old with Sentinel X300 System Cleaner, existing systems with Sentinel X400 System Restorer or Sentinel X800 Jetflo Ultimate Cleaner. If the system is already noisy due to deposits in the heat exchanger, Sentinel X200 Noise Reducer should be added together with Sentinel X100

Sentinel X100 is also available in Rapid-Dose™ and Concentrate format, or as Towel Rail Inhibitor.


1 litre of Sentinel X100 is sufficient to treat a typical domestic system of up to 10 radiators. Larger systems should be dosed with 2 litres. 


  • 1 litre bottle
  • 10 litre bottle
  • 20 litre cubitainer 


Open Systems: Dose via F&E cistern, via a by-pass feeder or use a Sentinel Dosing Vessel.
Sealed Systems: If the system is empty, add to any convenient point before filling. If full, use a Sentinel Dosing Vessel to inject via the filling loop or other access point. 

Physical properties:

Appearance: Clear colourless to pale blue or pale yellow liquid 
Odour: Mild
Specific Gravity: 1.12 (20°C)
pH (concentrate): 6.5 (approx)
Freezing point: -2.5°C 
X100 1L EST Comp

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The information below enables compliance with the Control of Substances Hazardous to Health Regulations.  

A Safety Data Sheet is available upon request. 

Sentinel X100 Inhibitor for Central Heating Systems 

An aqueous solution of inorganic and organic corrosion and scale inhibitors 

Health Hazards 

Not for use in potable water systems

Not considered hazardous to health


Keep out of the reach of children. 

Avoid contact with skin and eyes. 

Wash out empty container thoroughly with water before disposal 


Keep container tightly closed 

Store in cool, well ventilated area 


Flush spillage with plenty of water and wash to waste 

Fire/Explosion Risks


First Aid: 

Skin Exposure

After contact with skin, wash immediately with plenty of water. 

If irritation develops, seek medical attention 

Eye Exposure 

In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 

Keep eyelids apart 

Seek medical advice 


Rinse mouth with water

Do NOT induce vomiting!

Seek medical advice

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Sentinel Performance Solutions Ltd | The Heath Business & Technical Park | Runcorn | Cheshire | United Kingdom | WA7 4QX | 01928 588 330