solar thermal fluidSentinel R100 Heat Transfer Fluid for Solar Heating Systems

Features and Benefits

  • Ready to use concentration – no need for dilution
  • Effective frost protection down to minus 25°C
  • Resistant to degradation.
  • Provides effective corrosion protection for system metals.
  • Chemically & thermally stable components
  • Non-toxic and biodegradable
  • Buffered pH
  • Less frequent changing of the thermal fluid
  • Improved cost of operation of the solar system
  • Supplied in 20 litre tubs


Sentinel R100 Solar Thermal Fluid is a clear blue liquid based on propylene glycol solution. It has been designed for use as a thermal fluid in solar heating equipment such as flat plate and vacuum tube collectors where it ensures highly efficient heat transfer between the solar collector and the thermal store. Sentinel R100 is also optimised to provide freeze protection of the circuit even to 25°C.

The special inhibitors contained in Sentinel R100 provide superior protection to the metals normally used in solar installations against corrosion and deposits. Sentinel R100 prevents the surfaces of heat exchangers fouling and maintains thermal efficiency. The product is especially formulated to resist thermal degradation and so extend fluid life.

The efficient thermal transfer properties and superior stability of Sentinel R100 help towards reduced cost of system operation.

solar system cleaner fluidSentinel R200 – Solar Cleaning Solution

Ready-to-use cleaner for solar heating systems Sentinel R200

Features and Benefits

  • Ready to use – no need for dilution
  • Removes sludge and deposits from degraded thermal fluid
  • Cleans with only 20 minutes circulation
  • Effective at low or room temperature
  • Can be used with flushing machine
  • None foaming and easy disposal
  • Compatible with the construction materials of the solar system
  • Supplied in 20 litre tubs


Sentinel R200 is a specially formulated, mildly alkaline product designed for use as a cleaner for solar heating system circuits containing either flat plate or vacuum tube collectors.

The thermal fluids used in solar heating systems may degrade over time because of prolonged exposure to elevated temperatures.

This degradation process, which is indicated by a darkening of the fluid, not only reduces the lifetime of the thermal fluid, but also has the following adverse effects on the operation of the system:

  • Colour changes and viscosity increases
  • Thickening of the fluid and solid deposits which causes blockages
  • Reduces the diameter of the pipe work
  • Freezing point increases
  • pH decreases
  • The degraded fluid has a reduced heat transfer capability

In order to restore the efficient operation of the solar heating system it is necessary to drain the degraded thermal fluid, clean the system to remove any sludge, deposits or blockages, and refill the system with Sentinel R100 – a thermal fluid which is especially formulated to resist thermal degradation and so extend fluid life.