Yes, all Fernox internal leak sealers, such as Fernox Leak Sealer F4, are safe for use with combination and other low water content boilers.
They will not block valves or vents. Leak Sealer F4 Express is recommended for all pressurised systems as this can be added in 30 seconds via a radiator, filling loop or Fernox TF1 Filter, without the need to drain the system.
Normally a treatment will last the life of the system but an annual check to determine whether further dosing is necessary is recommended. If the system is drained, it will need to be re-treated with a further full dose of Protector. You can check if the system is properly dosed using a Fernox Protector Test Kit.
BS 7593:2019 recommends that the inhibitor should either be re-dosed at 5-year intervals or, a more comprehensive laboratory test is conducted every five years to provide a more in-depth analysis, and where needed, establish targeted action to resolve issues and restore system efficiency. The Fernox Water Quality Test includes everything needed to take a sample of the system water and
Power Cleaner is phosphate, nitrate and nitrate-free and is developed to exceed all regulatory and legislative guidelines in regard to the environment impact of the formulation. It is compatible for use in mixed metal heating systems, including aluminium.
