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Sentinel Leak Sealer

which is added into the system, is ideal when weeping joints and small leaks don't warrant immediate repair.

Sentinel Leak Sealer for Central Heating Systems

  • Easy to apply
  • Readily dispersible
  • Will not cause blockages within the system
  • Compatible with other Sentinel products
  • Suitable for all metals including aluminium
  • Compatible with elastomers
  • Non-toxic and non-irritant
  • Manufactured under a quality system conforming to ISO9001


  • 1 litre bottle

Sentinel Leak Sealer is for internal application to seal small leaks and weeping joints in all types of indirect heating systems including those containing aluminium components. A soft seal is formed, normally within 24 hours, but dependent on the rate of leakage and the temperature.


1 litre of Sentinel Leak Sealer is sufficient to treat a typical domestic system up to10 radiators. Larger systems should be dosed with 2 litres.
After dosing is complete, the system should be operated normally for at least 15 minutes - heat is beneficial.


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

White emulsion
Odour: Mild
Specific gravity: 1.0 (20?C)
PH (concentrate): 7 (approx)
Freezing point: 0?C