Protection for commercial heating and cooling systems against limescale, corrosion and freezing temperatures

Sentinel X500 is a multi-purpose inhibited antifreeze formulated to help control corrosion, scale, boiler noise and hydrogen gassing in all types of indirect heating systems & closed cooling systems including those containing aluminium components. It is an ideal product for biomass boilers requiring frost protection. If minimum levels are maintained the product ensures a permanent protection and does not need to be replaced. It is ideal for premises where the heating system is at a higher risk of freezing due to location, irregular use or building structure. 

Key features

  • Minimise risk of frozen heating system
  • Ideal for biomass boilers requiring frost protection
  • Enhanced limescale and corrosion protection
  • Protects all system metals against corrosion
  • Ensures optimum system efficiency
  • Prevents boiler noise
  • Prevents pin-holing
  • Helps prevent the formation of hydrogen gas

Available sizes

5L liquid X500L-4X5L-GB
20L liquid X500L-20L-DRUM
Larger sizes available upon request Please call 01928 704 330

The two main causes of system inefficiency are limescale and corrosion, contributing to problems such as heat exchanger or boiler inefficiency, noisy operation and system breakdown. Keeping a system healthy is integral to ensuring reliable and energy-efficient running, prolonging the life of the system and helping to achieve Carbon Reduction Commitment goals.

Properties where the system is vulnerable to low or sub-zero temperatures should be treated with Sentinel X500 Inhibited Antifreeze. If the premises are vulnerable to low temperatures, it becomes even more important to ensure the efficient running of a heating system. The Workplace (Health, Safety and Welfare) Regulations 1992 states that:

‘During working hours, the temperature in all workplaces inside buildings shall be reasonable.’

The associated ACOP goes on to explain that the ‘temperature in workrooms should normally be at least 16 degrees Celsius unless much of the work involves severe physical effort in which case the temperature should be at least 13 degrees Celsius.’

Once a system has been prepared using one of the cleaners from the Sentinel commercial cleaning range, add an inhibitor to prevent limescale build up or corrosion. For protection against limescale, corrosion and freezing temperatures, add Sentinel X500 Inhibited Antifreeze.

The dosage of Sentinel X500 will depend on the level of frost protection required (see below). A dosage of 20% by volume (ie 20 litres Sentinel X500 added for each 100 litres system volume) will provide frost protection down to -6°C (onset of freezing) and -10°C (bursting point). A dosage of 40% will protect down to -20°C (onset of freezing) and -28°C (bursting point). Further information is available on request. A dosage of 20% or more is needed to achieve the minimum concentration of corrosion and scale inhibitor.

The Sentinel Test Kit can be used to verify that this level has been reached. To determine the precise X500 concentration, a refractometer may be used; refer to the calibration graph below.

 For best results, it is recommended that systems are first cleaned and flushed in accordance with standard cleaning and commissioning protocols such as BSRIA Guide “Pre-Commission Cleaning of Pipework Systems” or similar Water Treatment Guidelines from industry organisations such as the Industrial & Commercial Energy Association (ICOM).

Ideally, as part of such protocols, new systems and those up to 6 months old should be cleaned with Sentinel X300 and older systems with Sentinel X400 or Sentinel X800 Fast Acting Cleaner. For systems or parts of systems (such as under-floor heating circuits) which operate at temperatures below 60ºC it is beneficial to sanitise the water circuits using Sentinel X700 following cleaning and flushing with the above products.  If the system is already noisy due to limescale deposits in the heat exchanger, Sentinel X200 should be added together with Sentinel X500. In systems which operate below 60ºC or spend extended periods out of commission, the addition of Senticide X700 to provide long term protection from bacterial activity should be considered.

Open heating systems:  partially drain the system to provide enough volume to accommodate the X500 and feed the product into an area of adequate flow or use a by-pass feeder.

Closed heating and cooling systems: If the system is empty, add the product to any convenient point before filling. Otherwise first partially drain the system to provide enough volume to accommodate the X500. Systems which are subject to the continual addition of make-up water need to be periodically replenished with Sentinel X500 to ensure that the recommended dose level is maintained.