Get in line

Sam Hayes of Fernox explores the benefits of incorporating an in-line filter on new build central heating systems.

When looking to purchase a property, there are a multitude of factors that influence potential new homeowners’ decisions. These range from the location of the property, the direction it faces, as well as the size of the rooms. There are also a host of contributing elements that cannot be changed once the property is built.

When purchasing a property for the long-term, home improvement website Plentific found that a quarter of young homeowners (aged 18-34) would rather improve their home than sell it. Adding long-term value to a property is therefore essential.

This is especially true when considering one of the most expensive amenities within a home – the central heating system. Both the boiler and system require a significant financial investment should either need replacing, so complying with the manufacturer’s warranty and maintaining the efficiency of a newly installed boiler is of paramount importance.

A central heating system fitted with an inline system filter conforms to industry best practice and ensures compliance with Part L of the Building Regulations. It also provides added value and peace of mind for any prospective buyers.

When water comes into direct contact with metal, a chemical reaction known as electrolytic corrosion occurs. This process produces iron oxide deposits and sludge, which can circulate and coat internal components with a thick, sticky paste called Magnetite. In hard water areas, limescale can also circulate within the system and attach to vital components, such as the heat exchanger or pump.

The build-up of corrosion deposits, sludge and limescale negatively impacts upon the system’s overall energy efficiency – British Water estimates a 1.6 mm coating of limescale on a heating element can reduce efficiency by up to 12 per cent. This results in fluctuating hot water temperatures and the overworking of the boiler, with the overall system efficiency being decreased. Consequently, fuel bills increase, while the lifespan of the boiler is reduced.

According to Sedbuk, an ‘A’ rated boiler reduces its ‘90 per cent or above’ efficiency rating in as little as six weeks after installation if the system water has not been properly treated with inhibitor and corrosion has formed.

This issue of corrosion is even more pertinent considering the design of modern energy efficient ‘A’ rated boilers. In order to achieve the highest efficiencies, boilers have become smaller and more compact, with narrower internal channels. This makes the boiler particularly vulnerable to any circulating debris, sludge or scale, as it can easily become trapped in the heat exchanger, causing a blockage and potentially damaging internal components.

For a newly commissioned boiler, the system should be dosed with a quality chemical inhibitor in accordance with Part L of the Building Regulations and leading boiler manufacturer warranties.

When specifying the use of an inhibitor, it is important to use a BuildCert certified product, which meets or exceeds minimum quality standards. Recognised as industry best practice, the use of filtration technology alongside chemical water treatment is also included within the supplementary information of the Domestic Heating Guide, which states: “a filter can also be fitted to the central heating circuit to help maintain the efficiency and reliability of the system.”

Capturing circulating debris and containing it for safe removal, an in-line filter offers on-going protection of the boiler against damage from dirty system water.

Selecting a filter that collects both magnetic and non-magnetic debris is essential. It is recommended to look for filters that offer dual protection capability by combining hydrocyclonic action or hydronic particle separation (HPS) technology, to capture copper, zinc or aluminium corrosion, with a powerful Neodymium magnet to trap iron oxide contaminants.

Leading manufacturers provide a range of filters of various sizes to allow for installation in small or confined spaces. Also, for different aesthetic finishes, developers should look to ranges that incorporate both plastic and brass nickel-plated solutions to provide the ultimate choice and flexibility. Available with easy to maintain warranties, a filter body parts warranty can often extend to 25 years.

In addition to providing an energy efficient and reliable heating system, the use of an in-line filter ensures that on-going servicing or maintenance of the system is quick and easy. This allows chemical water treatments to be dosed via the filter in as little as 30 seconds and a full powerflush clean to be achieved via the unit. In-line filter technology offers lasting benefits to any potential householder.

For housebuilders and developers, adding value to essential amenities such as the central heating system is of significant importance. By incorporating an in-line filter, a ‘belt and braces’ approach to protecting the boiler can be offered. This provides peace of mind and confidence that the system will maintain its efficiency throughout its lifespan, and not suffer early failure due to circulating contaminants.

Sam Hayes is filter project engineer at Fernox