News

Flushed with success

Published: 19-02-2009

In the first of a series of new monthly columns, Phil Bunce, training manager for Worcester Bosch Group, will be tackling some of the latest issues to affect the heating and plumbing industry, offering tips and advice to help make your business as commercially viable as possible. To kick off, the column will look at the importance of water treatment to make sure you're up-to-date with the latest rules and regulations. Phil says:

"As you are no doubt aware, it is now detailed in Part L of the Building Regulations and within the Domestic Heating Compliance Guide that when it comes to fitting a new boiler, installers are also required to thoroughly cleanse the heating system. Put simply, this means you should be firstly flushing a property's system when installing a new boiler and secondly following it up by inhibiting the system to ensure you fully meet the latest legal requirements.

"Treatment of water in domestic central heating systems is important for a number of reasons, including:

• Minimising the corrosion of metals within the system
• Inhibiting the formation of sludge
• Inhibiting the growth of microbiological organisms
• Maintaining or restoring the energy efficiency of the system through a combination of the above effects

"As the last point indicates, water treatment can vastly affect the overall efficiency of the boiler. If the existing quality of water in the system is not of a decent standard this is likely to reduce the longevity of the heating system, meaning the boiler may breakdown sooner or even cause noise problems.

"Very recently, Worcester carried out a sample survey to analyse the mains water of 90 central heating systems. Of those 90 systems checked, we discovered that less than half were treated correctly and some of them hadn't had any element of chemical flushing at all.

"This issue is significantly affected by the fact that in the UK many new boilers are installed within existing heating systems where old radiators and pipework are commonplace. It is also quite likely the system was previously an open vent system with of course an open feed and expansion arrangement which is more likely to allow oxygen ingress than a sealed primary system.

"Most crucially, additional tests carried out by an independent laboratory found that the efficiency of the heating system, when it was flushed and correctly inhibited, resulted in a 6% improvement in efficiency in comparison with an old system that had not been properly treated. This 6% effectively drops boiler performance out of the top SEDBUK band and demonstrates that the highest possible boiler efficiency is significantly more difficult to achieve if the water travelling through the system is untreated and of a poor quality.

"Frequently a property's existing heating system is 'open vent', which means the system is not sealed from the atmosphere subsequently allowing oxygen to enter the water. As a result sludge builds up in the pipework, which can cause all sorts of problems if left untreated.

"These findings suggest that a much greater focus is needed on water treatment. Failing to properly treat system water not only means customers being left with an incomplete installation that doesn't meet the requirements set by the Government, but also means that your customer's new boiler will very rapidly lose the efficiency levels that it has been installed to provide. Flushing and cleansing a system properly, followed by the proper inhibiting, will ensure the boiler and the central heating system operate at optimum efficiency providing improved fuel consumption and reduced energy bills for the householder and a system that performs as it should.

"My top tips for a properly cleansed system include:

• Use only products from water treatment manufacturers participating in the DWTA, which includes companies such as Fernox and Sentinel.
• As a general guide for flushing (and in accordance with the manufacturer's recommendations), flush the system at least once prior to cleansing without turning on the boiler to remove loose debris.
• Add the cleansing agent (again in accordance with manufacturer's recommendations) and circulate within the system for a minimum of one hour, at normal operating temperature. A longer period of time, up to 48hours, would be more beneficial to the cleansing process especially if heavy sludge deposits are present.
• Drain the system thoroughly at least twice to remove the cleaning agent.
• Once cleansed thoroughly, add a mixed metal corrosion protector to protect against the formation of scale, corrosion and microbiological growths.
• Complete the retreatment label supplied with the corrosion protector treatment and fix to the boiler.

"The above is intended as a quick guide and could help make it easier to recommend the benefits of water treatment to your customers. To ensure you have all the latest up-to-date knowledge, I would also recommend attending a training course. Many manufacturers run informative training courses and, as a result of installer-demand, at the end of last year Worcester launched a new one-day water treatment training course to help installers understand the full requirements of BS7593:2006, which is now detailed within Part L of the Building Regulations.

"Designed in partnership with Fernox and Sentinel, the course combines theoretical as well as practical exercises, gives examples of the typical problems found in central heating systems, the benefits of water treatment, correct product selection and the methods of system cleansing. We will also show installers practical tasks such as powerflushing a system, correct use of TDS meters and system water testing. The course has also been certified by LOGIC Certification in recognition of the additional skills and knowledge that would be gained by installers who successfully complete the course."