• Fernox F1 central heating inhibitor: This Fernox F1 central heating inhibitor protects sealed and open vented systems by preventing rust, limescale, and internal corrosion in radiators and boilers
• Inhibitor for central heating: Inhibitor for central heating systems that complies with BS 7593:2019 and helps maintain reliable heating, reduce system wear, and extend component lifespan
• Radiator inhibitor and rust inhibitor: Dual-purpose radiator inhibitor and rust inhibitor that reduces sludge build-up and improves circulation for faster, more even radiator heat
• Rust cleaner and radiator flush compatible: Use after radiator flush with Fernox F3 or F8 to stabilise pH and act as a rust cleaner, keeping internal surfaces clean and scale-free
• Rust treatment and system protector: Though classified as an inhibitor, this product also serves as a rust treatment and functional system protector, helping reduce radiator noise and boiler strain
• Lower heating bills and energy use: By maintaining system efficiency, this central heating inhibitor helps lower heating bills, reduce gas consumption, and support long-term energy savings

Fernox F1 Central Heating Inhibitor 500 ml is a trusted inhibitor for central heating systems, designed to provide long-lasting protection against rust, scale, and corrosion. This Fernox F1 inhibitor is ideal for homeowners and professionals looking to preserve system health, extend boiler life, and improve efficiency. Fernox F1 Protector functions as a radiator inhibitor, guarding your radiators and boiler components from corrosion, sludge, and scaling. It is suitable for use in all system types, including mixed-metal and aluminium installations. Fernox F1 protector central heating solution also works with both open vented and sealed systems, offering wide compatibility. Each 500 ml bottle treats systems up to 130 litres in volume, equivalent to 16 radiators or 250m2 of underfloor heating. For optimal performance, use Fernox F1 after a radiator flush or cleaning with Fernox F3 or F8. This locks in long-term protection and also helps improve fuel efficiency and can achieve up to 15% gas savings per heating cycle. For systems requiring maintenance or cleaning, this product supports the effects of a radiator flush and promotes cleaner system operation. Engineers and DIY users trust Fernox F1 for its industry-leading protection. The formula acts as an inhibitor, preventing debris, corrosion, and scale before they cause blockages or performance issues. Compatible with other Fernox products, this central heating inhibitor is safe, non-toxic, and fully approved by NSF, KIWA, and Belgaqua. For best practice in line with BS 7593:2019, systems should be checked annually and re-dosed every five years to maintain performance.