Protecting heating and cooling systems

Protecting whole heating and cooling systems is now the industry standard thanks to BS 7593:2019. Francine Wickham, global marketing director at Fernox, explains the five steps to success and products that can help...

One small change in rules but a giant leap for best practice came just under a year ago from British Standards.

The roll-out of BS 7593:2019 was a massive shift in approach from focusing on sections of an installation to standardising best practice in the whole system.

It set the new British Standard for preparation, commissioning and maintenance of domestic central heating and cooling water systems.

Behind it are the key issues that everyone in the industry is grappling with: energy efficiency, environmental concerns and sustainability. A top performing system will use less energy, will consistently deliver heat or coolness and ensure the longevity of parts meaning less equipment is scrapped.

The goal is to keep the system working at optimum efficiency and extend system life.

Central to the new standard is a system of regular checks and testing against a benchmarking list. As ever, record keeping is also vital to be able to show that the work has been done.

There are a number of manufacturers creating products for you to choose from in order to meet the new standards. Fernox is one of them.

Francine Wickham, the company’s global marketing director, sets out the checklist for a best-practice approach to system protection.

The most significant amendments require installing an in-line system filter and regularly testing the system to highlight and rectify any issues. To comply with BS 7593:2019, it is important for installers to follow five steps: clean, guard, protect, maintain and test.

Step 1: Clean

Installers should clean central heating systems to remove any sludge and debris. This can be achieved by using a recognised cleaning method such as powerflushing, mains pressure or gravity cleaning.

Only after the cleaning process has been completed can installers dose the system with chemical water treatment and install an in-line filter. Systems should also be cleaned before the boiler is installed or when a new boiler has been isolated from the rest of the system.

Step 2: Guard

To prevent the build-up of sludge and debris within the central heating system, installers should install an in-line filter. A filter will provide continued protection by capturing and containing any debris and thus preventing it from re-entering the system. For the best results, installers should opt for a filter that removes both magnetic and non-magnetic debris. For example, the Fernox TF1 Filters use Hydronic Particle Separation technology for maximum protection. Installing a filter will maintain the efficiency of the system and extend its life cycle.

Step 3: Protect

To safeguard a central heating system from the damaging effects of corrosion, sludge and scale build-up, installers should dose the system with the correct quantity of chemical water treatment products and should apply inhibitors and protectors. Shielding against corrosion debris helps to reduce boiler noise, radiator or pipework blockages and boiler breakdowns.

Fernox has made it simple for installers to dose central heating systems correctly by re-formulating its chemical range. Now, the ‘F’ range and Express range of products can treat systems up to 130 litres, 16 radiators, or underfloor systems up to 250m2 – which means one bottle is suitable for use in 97% of UK homes.

Step 4: Maintain

To ensure filters continue to work efficiently, it is important for installers to regularly clean the filter to remove any sludge or debris that has been captured. BS 7593:2019 recommends servicing of in-line filters should be included as part of the re-commissioning process, ideally as part of the annual boiler service and routine maintenance.

Step 5: Test

Under BS 7593:2019, installers are urged to check inhibitor levels annually and conduct a laboratory test every five years, to identify and prevent any issues and keep the system working at optimum efficiency and extend system life. This can be achieved with a system water test. If any issues are highlighted during the testing process, installers can easily rectify them.

It is also important for installers to note the recent changes that have been made to the Benchmark commissioning checklist. Previously, installers had to state if they had used a cleaner or inhibitor – however, it now asks which brand and product the installer has used. The installation of a filter is also listed, and the inclusion of water softeners has been added to the scale reducer category.

Industry standards, such as BS 7593:2019 and the updates to Benchmark, are vital for standardising practices across the plumbing and heating industry and ensuring that central heating systems are properly protected and maintained.

More information

To find out more about the range of Fernox products that can help you adhere to BS 7593, speak to your Fernox representative or visit

This article first appeared in the May/Jun 2020 issue of P&H Engineering, the magazine for members of the CIPHE. Find out how to join here.

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