This concentrated universal cleaner is designed for solar systems, and removes degraded solar heat transfer fluids, sludge and blockages. In doing so, this product rapidly restores efficiency to existing solar thermal systems.

  • A concentrated universal cleaner for solar systems
  • Removes degraded solar heat transfer fluids and sludge
  • Clears blockages
  • Restores efficiency of existing systems
  • Fast acting
  • Non-foaming
  • Suitable for use with all makes and models of solar systems


Fernox Solar Cleaner is suitable for use within solar thermal installations that conform to BS EN 12976 and BS 5918. Drain the system of solar fluid from the lowest point on the system into a suitable container for disposal. Fernox Solar Cleaner is supplied as a concentrate and should be diluted with mains or demineralised water using one bottle for every 25 litres. Refill the system with cleaner solution and circulate for 15-20 minutes. Drain or pump the used cleaner to a suitable container for disposal. Refill the system with water and circulate for 5-10 minutes to remove residual cleaner from the system and dispose. After flushing the pH of the mains water and final flushing water should be the same. If the mains water pH is lower then repeat flushing procedure. When the flushing procedure is complete, ensure that all pipes are drained so no water remains in the circuit before filling with Fernox Solar S1 fluid.

Compatibility with non-metallics

Fernox Solar Cleaner is compatible with all non-metallics commonly found in solar thermal installations.

Quality and Environmental

Fernox Solar Cleaner is manufactured according to BS EN ISO 9001 and 14001.

Physical Properties

Composition: A concentrated aqueous solution of specifically formulated cleaners and inhibitors
Appearance: Clear, colourless liquid
Odour: Slight
Density: 1.04 g cm-3
pH [conc]: 7.3
Solubility: Easily soluble in water 

Packaging, Handling and Storage

Fernox Solar Cleaner is supplied as a concentrate in 500ml bottles. Fernox Solar Cleaner is classified as non-hazardous and non-irritant, but as with all chemicals, keep out of the reach of children. Do not take internally. In case of contact with eyes or skin, rinse immediately with plenty of water. Dispose of degraded thermal fluids and used cleaner solution according to local regulations.

Please contact the supplier to check availability of stock