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Maintain the design specification and
energy efficiency
Restore energy efficiency
Inhibit the formation of scale and sludge
Minimize corrosion of system metals
Express format for easy use
Good practice dictates that hydronic central heating systems should be thoroughly cleaned and
flushed before installing a new boiler, after which a chemical inhibitor should be added to ensure the
system is protected from corrosion, scale and sludge build-up. These procedures should also be
employed when major work is carried out on a system. A clean, protected system helps ensure that
the heat generated by the boiler is transmitted efficiently into the house over the long term
Test Procedure
1. Prior to cleaning and flushing, use the enclosed pH test strips and color coded chart to measure the
initial pH of the system water as a reference guide.
2. Check boiler manufacturer’s instructions regarding system cleaning prior to commencing work.
3. Best practice is to clean and flush the heating system with the old boiler still installed prior to
installation of a new boiler.
4. Drain the system water.
5. Fill the system with fresh water.
6. Add Fernox Cleaner F3 into the system.
7. Run up to temperature for a minimum of one hour. Ensure that all the system is fully open to allow
complete cleaning. Check that all zones including all radiators (if present), are heating up and there
are no cold spots. If heating the system is not possible, activate the circulating pumps and allow to run
for up to 9 days for a thorough clean.
8. Drain and flush the system thoroughly in both directions to remove the cleaning agent and any
debris until the water runs clean. Use of a powerflusher is preferred.
9. Fill the system with fresh water.
10. Add Fernox Protector F1 to provide long term protection against corrosion and limescale, and
maintain efficiency. Circulate around the system for equal distribution.
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11. Test the inhibitor levels present using the Fernox Protector Test Kit.
Shake Reagent bottle before use.
Fill the 30ml graduated test vessel to the 10ml mark with tap water.
Holding the Protector Reagent bottle exactly vertically upside down, add one drop (the
solution should turn blue).If the solution does not turn blue but remains clear or turns yellow
immediately, count number of drops as 0 and move to step 4.
Continue to add Reagent dropwise, mixing between each addition. Count the number of
drops required to turn the solution yellow/orange.
Repeat steps 1 to 3 above with a sample of the system water.
Deduct the number of drops of tap water from the number of drops of system water to give
the difference.
If the difference is less than the optimum given below, add additional Protector
Alphi 11
Protector F1
Recommended Dose/100L
6.5 US gallons - 25 liters (-11ºC/12.2ºF)
7.8 US gallons - 30 liters (-15ºC/5ºF)
9.1 US gallons - 35 liters (-18ºC/-0.4ºF)
10.4 US gallons - 40 liters (-22ºC/-7.6ºF)
1 pint - 500ml
No of drops difference*
10 minimum
12 minimum
14 minimum
16 maximum
9 optimum
*Difference between system water and mains water.
(Number drops system water sample – number drops mains water sample)
12. Check the system pH level using a pH test strip provided and color coded chart. The pH value of
the system water must be between 7 and 8.5.
13. If the Fernox Protector Test Kit and/or the pH test strip do not show positive results, add additional
Fernox Protector F1. Repeat both tests using a fresh pH test strip until achieving the desired results.
Packaging, Handling and Storage
The Fernox Boiler Commissioning Kit is supplied as with full instructions and is non-hazardous
reagents. Keep
out of reach of children.
1 x Fernox Protector F1 17.6oz (500ml)
1 x Fernox Cleaner F3 17.6oz (500ml)
4 x Fernox pH Test Strips
Instruction Leaflet
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