FERNOX F2 Central Heating Boiler Noise Silencer - 500ml. Boiler Noise Silencer F2 is specifically designed to reduce both boiler noise and kettling, a common symptom of a scaled system. Furthermore, with just one 500ml recyclable bottle, you can treat up to 130 liters of system water (equivalent to 16 radiators) and cover an area of 250m2 in underfloor systems.
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