Sentinel
Sentinel X100 Central Heating Inhibitor 1 Litre
A 1-litre leave-in inhibitor that protects central heating systems from limescale and corrosion, treating up to 100 litres of system water.
At a glance
£15.42
£12.85 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
Sentinel X100 is a leave-in liquid inhibitor for central heating systems, formulated with TripleTech anti-corrosion technology to protect against limescale and corrosion across multiple system metals. It is pH neutral and suits hard, soft and artificially softened water, and is Energy Saving Trust recommended for maintaining system efficiency.
Signs this part needs replacing
- Black or discoloured water when bleeding a radiator
- Banging or kettling noises from the boiler heat exchanger
- Cold spots at the bottom of radiators (sludge/scale build-up)
- Boiler cutting out on overheat or losing efficiency
- System recently drained, flushed or had a part replaced without re-dosing
Before you order
- Confirm your system is open-vented or sealed and whether it contains aluminium components
- Use a test kit to check existing inhibitor levels before topping up
- Re-dose after any drain-down, power flush or major repair
- Isolate the relevant valve or cistern before dosing
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| SPECIAL OFFERS Sentinel | — | — | — |
Documents & drawings
Everything we hold for this part. Where a document exists but we don't hold it, the technical team will source it from the manufacturer — usually the same working day.
No documents held for this part. The technical team will source them from the manufacturer — usually the same working day.
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Tell the parts assistant what it's going into — the appliance make and model, or the GC number off the data badge — and it will check this part is on the fit list.