Alphi-11 Protector 5 & 55 gallons

Product Code: 155738-0005, 155738-0055

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Alphi-11 Protector is a combined antifreeze & inhibitor providing protection against internal corrosion and limescale formation.


Antifreeze Protector Alphi-11 is a combined antifreeze and inhibitor product, which provide protection against internal corrosion and limescale formation in domestic central heating systems . Available in 5 gallon and 55 gallon liquid product. Antifreeze Protector Alphi-11 is suitable for use with all metals and materials commonly used in heating systems. For long -term protection ensure concentration levels are maintained and checked annually as part of the boiler or system service. Antifreeze Protector Alphi-11 is compatible with all other Fernox products.


  • Protects against corrosion and limescale
  • Combined antifreeze and protector
  • Prevents limescale build-up
  • Compatible with all metals and materials commonly used in heating systems
  • Non-toxic, environmentally friendly
  • Protects heating and chilled water
  • 5 gallons: 155738-0005
  • 55 gallons: 155738-0055
  • Buildcert
  • kiwa
  • Energy Saving Trust
  • kiwa

Physical Properties

Fernox Antifreeze Protector Alphi-11 contains mono-propylene glycol.
Colour: Colourless
Odour: Aromatic (slight) }
Form: Clear liquid
pH (conc.) 6.9
pH ( 25% solution): 6.4 – 7.4
SG: 1.04 at 20°C

25% 30% 35% 40% 50%
12.2°F 8.6°F 1.4°F -7.6°F -29.2°F
Burst point °F
0 -20 -40 -60 -80


Application and Dosage

The minimum recommended “in-use” concentration of the product is 25% in order to ensure adequate corrosion protection. This concentration will protect down to  12.2°F. A concentration of 40% will protect down to -7.6°F. Antifreeze Protector Alphi-11 can be introduced via the feed and expansion tank or other suitable point of application, e.g. radiator, using a Fernox Injector. Introduce into the system after having drained a quantity of water at least equal to the amount of Alphi-11 to be added. Engage the circulating pump and have the system online for a few hours in order to achieve an even distribution.

Packaging, Handling and Storage

Fernox Antifreeze Protector Alphi-11 is supplied in 5 and 55 gallon containers. Fernox Antifreeze Protector Alphi-11 is classified as non-hazardous and non-irritant, but as with all chemicals keep out of reach of children. Do not mix with other chemicals with the exception of Fernox products. Do not take internally. May cause an allergic reaction. Contains 1,2-benzisothiazol-3(2H)-one. In case of contact with eyes or skin, rinse immediately with plenty of water.