Nigel Jefferson, commercial director, Secon, discusses why inspecting the condition of heating circuits is of the utmost importance when installing new equipment or carrying out maintenance. ​​​​​​​

Whether installing a new heat generator or carrying out repairs to a heating system, there is one thing that is constantly overlooked, the condition of the heating circuit. Many existing heating systems will have a build-up of sludge and corrosion debris in the pipework and radiators. This reduces the system's efficiency and drastically shortens the life of the component parts such as boilers, heat pumps, circulating pumps, valves, etc.

It is essential that before installing any new heat generator that the system is properly cleaned and treated, and the process is simple.

First, carry out a basic water test with a suitable Water test Tube; this will give you the water's turbidity and indicate what is required. This can be from clean and no action needed to heavy residue, and a full clean and powerflush are required.

It is important to get the cleaner into the system before fitting the new heat generator, so add the cleaner whilst the old boiler is in position and circulate, ideally for a day but a minimum of 1 hour under heat conditions.


If a powerflush is required, a suitable flushing machine should be used in conjunction with a magnetic powerflushing filter. This will remove all the magnetite and rust from the system.

Once cleaned, if it is a low-temperature system, it is advised to add a biocide to disinfect and clean the pipework to prevent any microbiological fouling producing jelly-like deposits (fungal growths).

The system can then be filled and dosed with a suitable inhibiter which, in conjunction with an in-line filter, will help maintain the system components and efficiency for years to come.

It should also be noted that system chemical treatment is a must for compliance with BS7593:2019, the Benchmark scheme and manufacturer's warranties.

Secon stock a wide range of Fernox fluids and filter systems available from stock for next day delivery.