• Advanced Biocide Protection: Fernox F7 biocide eliminates bacteria, fungi, and algae to help maintain clear water flow and protect central heating components
• Suitable for Underfloor Heating: Designed for systems with low flow or intermittent use, where microbial growth is more likely to cause performance loss over time
• Helps Prevent Internal Damage: Failure to treat biological contamination may lead to sludge, corrosion, restricted flow, bad odours, and reduced system lifespan
• Compatible with Additives: Works with all system metals including aluminium, and should be used alongside an inhibitor such as Fernox F1 Protector
• Effective and Easy to Apply: A single 200 ml bottle treats up to 150 litres of system water or 250sq/m of underfloor heating, using a simple one-step dosing method through a radiator, dosing pot, or filling loop
• Not for Potable Water Systems: Fernox F7 biocide is designed for closed-loop heating systems only and must not be used in any application involving drinking or domestic water supply

Fernox F7 Biocide is a broad-spectrum microbial control additive designed for use in domestic and light commercial central heating systems. It is used to prevent and eliminate contamination by bacteria, fungi, and algae, which may contribute to the formation of sludge or biofilm within closed loop water systems. This product is particularly recommended for use in low-temperature or intermittently used circuits, including underfloor heating systems, where microbial activity is more likely to occur. If left untreated, microbial contamination may impair heat transfer, reduce flow, and contribute to blockages or corrosion. LavaTap - Fernox F7 Biocide as part of a curated range of heating system maintenance solutions. F7 is compatible with all common system materials, including aluminium, and can be used in conjunction with Fernox inhibitors and leak sealers. One 200 ml bottle treats up to 100 litres of system water. It should be added via an appropriate dosing point and circulated for at least one hour. For continued protection, use in combination with a system inhibitor such as Fernox F1.This product is not suitable for potable water systems. Always follow label instructions and consult the Safety Data Sheet (SDS) before use.