Underfloor Heating Water

Water based underfloor heating systems must be filled with water using either a filling pump or simply mains water pressure. This is done during system commissioning and at this stage we recommend that an antifreeze additive is added to the water, one such as Sentinel X500 is what we usually recommend. This will protect the system during install as the pipe may be vulnerable to freezing during winter installations particularly before the building is weather tight. X500 does not degrade over time so does not need to be renewed or replaced so will provide long-term protection even after the construction process is finished.

Using a reservoir and filling pump, a 20% concentration will give protection to sub-zero temperatures. As an example, a 5 litre bottle of X500 will be enough to treat a system to 20% concentration with approximately 200 metres of our 16mm PEX-AL-PEX pipe.

If you would like to perform a calculation yourself one metre of our 16/2 pipe contains approximately 0.113 litres of liquid or conversely 8.842 linear metres of 16/2 pipe will contain 1 litre of fluid.