FERNOX F4 leak sealer ,500ml (LSI)

£20.58 inc. Tax
£17.15 ex. Tax


FERNOX F4 Central Heating Leak Sealer

Fixes central heating system pressure loss due to weeps and leaks


  • Easy to use - leave in the system permanently
  • Compatible with Fernox F1, F2 and F3 products
  • Compatible with all metals and materials, including aluminium
  • Does not cause pump or air vent blockages


Concentrated to clean 10 radiators or 100 litres

For open vented systems add via the header tank, for sealed systems add via the filling loop or radiator

Not for use in single-feed indirect cylinders

Extra Information

Water Treatment
Leak Sealer