Instructions / Assembly

V.001
When using Cleaner F3 Express with a powerflushing unit, cleaning should be completed within an hour.
Use dynamic flushing with plain water until the water is clear, testing with the TDS meter as above to ensure
through flushing.
Refill the system adding a suitable Fernox Protector for long term protection against corrosion and
limescale.
In single feed indirect cylinders, e.g. “Primatic” or similar, potable water chemicals must be used.
First drain and refill the entire system with plain water. For optimum results the entire system, including drop
feed radiators, where fitted, should be completely drainable. 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 the surface water drain.
For open vented systems add Fernox Cleaner F3 Express via the header tank. For sealed systems add via
a radiator using a Fernox Injector.
When cleaning existing systems sludge and debris should be dispersed for at least one hour at normal
operating temperatures. However, to remove hardened iron oxides and limescales, the cleaning time can be
extended to 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 Cleaner F3 Express may be necessary in some cases.
Drain and flush the system thoroughly to remove the cleaning chemical and debris. At least three complete
changes of water are likely to be required. This is a crucial part of the cleaning process and must be carried
out correctly. Use a rinse test meter such as the Fernox TDS meter to ensure that the Total Dissolved
Solids have been satisfactorily removed. The system can be regarded as being thoroughly flushed when the
system water value is within 10% of the mains water value. Differences over 10% mean that significant
cleaner residues have been left in the system and further flushing is required. If not removed, cleaner
residues will promote corrosion and negate the cleaning process.