Core products for central heating systems

Core products for central heating systems

Richard Crisp, Head of Chemistry at Fernox highlights the core products that trade professionals should always have to hand to tackle the most common issues found in central heating systems.

When it comes to central heating systems, there are a range of issues that could result in a homeowner seeking out a professional’s advice and services. The good news is that, once identified, many of them can be easily rectified, and managed with the use of the correct, high quality products.

  • FernoxF2.2
  • FernoxF2

Boiler noise

If you have checked the boiler for mechanical faults, and have found everything to be in good working order, then in all likelihood, the noise will be due to limescale deposits on the heat exchanger.

When limescale forms on the inside of the pipework, it creates an uneven surface and the formation of crevasses. Due to the surface tension of water, it cannot fill these crevasses. Instead, steam and air form bubbles in these gaps and when the bubbles pop, they create noise. This noise is also known as ‘kettling.’

To remedy this, a noise silencer chemical can be used. Products such as Fernox Boiler Noise Silencer F2 will work to reduce the surface tension of the water in the central heating system. The water is then able to fill the crevasses caused by the limescale build-up. This prevents any steam or gas from settling in the crevasses, which means no noise is produced. With no system drain down required, the problem can quickly be resolved, and the silencer can be left in the system permanently.

To watch an explanatory video on Fernox Boiler Noise Silencer F2 visit

Problems with underfloor heating

Low temperature or underfloor heating circuits are at a higher risk from the formation of bacterial slimes, algae and biofilms. If left untreated, these can cause blockages resulting in a sluggish, less efficient system or even breakdown.

To treat, simply dose with a high-performance chemical treatment designed to remove bacterial contamination. It is important that the product chosen can work to clean the system in the short-term and provide continued protection against bacterial contamination and the build-up of harmful substances such as algae, jellies and biofilms.

Fernox Biocide F7 achieves this with the inclusion of two active ingredients – the formulation is Methylisothiazolinone (MIT) and Methylchloroisothiazolinone (CMIT) based.

Find out more and see this product in action at

  • FernoxF4
  • FernoxF4.2

Leaking pipes

A slow leak or weep anywhere in the central heating system’s pipework could result in pressure loss – and if left untreated, could lead to boiler breakdown. As isolating the source of a small leak and replacing pipework can be time-consuming (and costly for homeowners), it is recommended to use an internal leak sealer in the first instance.

Leak sealers can be easily dosed into the central heating system – in the same way that you would use other chemical water treatments such as an inhibitor. Once added to the system water, a leak sealer only starts to work when it comes into contact with oxygen (the leak source). The molecules in the formulation react with each other to bind and polymerise. The polymer then seals any holes in the pipework, even to microscopic level, thereby stopping leaking and pressure loss.

Products such as Fernox Leak Sealer F4, are safe to use as a precautionary and corrective measure, when pressure loss has occurred, but the leak site isn’t obvious or visible. This is because the chemical reaction that causes the product to bind and polymerise to seal the leak only occurs if oxygen is present, so there is no risk of blocked pipes.

Watch Fernox Leak Sealer F4 in action at

Colder weather

When pipes are situated in unheated areas such as the loft or are externally located, they can be prone to freezing. This is a common problem for unoccupied premises, garages and static caravans. As the pipes freeze, the flow of water becomes restricted, which causes the pipes to block and the system to fail. Frozen water within the pipes expands creating pressure – and this can result in pipes bursting, leading to major leaks and even flooding.

When the sun is shining, it’s easy to ignore this potential risk, but prevention is better than a cure. Prevent this from occurring by dosing the system with an antifreeze product. For example, Fernox Antifreeze Protector Alphi-11 prevents the water molecules from binding together and forming ice, keeping the system water circulating normally. In addition, Antifreeze Protector Alphi-11 includes a high-performance inhibitor, which stops corrosion and scale formation – keeping the system working at optimum efficiency.

See Fernox Antifeeze Protector Alphi-11 in action at

To find out more about Fernox and its range of water treatment products visit

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