One 500 ml bottle of Fernox Power Cleaner F8 is sufficient to clean a large domestic central heating system (130 litres) which covers 97% of UK domestic housing stock. Additional/repeat applications of Fernox Power Cleaner F8 maybe necessary for systems which have more than 130 litres or 16 radiators, or if systems are very heavily sludged.
First, drain and refill the entire system with mains water. For optimum results, the entire system, including drop feed radiators where fitted, should be completely drained. Preferably, full bore gate valves with hose connectors should be provided temporarily for this purpose. Motorised and thermostatically controlled valves must be set so that no part of the system is closed off during cleaning or rinsing. Discharges must be made to the foul drain and not to surface water drain.For open vented systems add PFernox Power Cleaner F8 via the header tank. For sealed systems add via a towel rail, a TF1 system filter or another suitable dosing point.
Power Cleaner F8 can also be used in conjunction with a powerflushing machine. In this case, please refer to the unit manufacturers instructions. Power Cleaner F8 should be circulated for a minimum of one hour at normal operating temperature. However, to remove hardened iron oxides and limescale, the cleaning time can be extended for up to one week under the normal heating cycle. If a radiator still has a cold spot after one hour, increase the flow through the radiator by closing the valves on the other radiators.
An additional or repeat dose of Fernox Power Cleaner F8 may be necessary in some cases. Drain and flush thoroughly, at least twice, until the water runs clear. When using Power Cleaner F8 with a powerflushing machine, use dynamic flushing with mains water until the water is clear. Refill the system adding Fernox Protector F1 (or Fernox Protector+ Filter Fluid for systems with an in-line system filter) for long term protection against corrosion and limescale. In single feed indirect cylinders, e.g.”Primatic”or similar, potable water chemicals must be used.
