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A spotlight on summer servicing

As schools prepare for the summer holidays, Steven Evans, National Sales Manager at Potterton Commercial, discusses boiler annual servicing

Posted by Lucinda Reid | July 15, 2017 | Facilities management

Summertime maintenance and servicing is an essential activity to make sure that the heating system is ready for the start-of-term in September and the winter season thereafter. It’s not a process that should be skimmed over to save time and cost; key aspects of the boiler and heating system should be checked and cleaned to make sure it is operating safely and efficiently. But by choosing a system that operates in a way which minimises wear and tear, servicing and maintenance can be made easy.

Burn right

A key component of a boiler’s annual servicing, flue gas analysis tells you how clean and efficiently the boiler is burning. By looking at the oxygen and carbon dioxide levels in the flue gas analysis, an engineer will be able to determine if the boiler is burning the right mixture of gas and air. It is common for the test to be done before and after cleaning the heat exchanger. If the boiler is burning cleanly, you can be reassured that both the school’s energy bill and carbon footprint is minimised, and that the boiler is not emitting dangerous gases.  

Deep clean

Debris and carbon on the heat exchanger creates a coating which means that heat cannot be transferred efficiently to the water sections of the boiler. After a visual inspection, the service engineer will manually clean the heat exchanger to remove any build-up. 

The burner will also be removed and cleaned to ensure that the boiler will continue to burn gas in the combustion chamber safely, properly and efficiently.

Water works

A water sample should be taken from the system to determine pH levels, cleanliness, and detect the presence of contaminants and limescale in the system. Not only will the results tell you how well the current water treatment regime is working, but also if the system needs to be flushed or treated further. Systems that are corroded become blocked with sludge and debris whilst limescale can build up on heat exchange surfaces. Both will cause the boiler to run at higher for longer. This is why testing and treatment of system water is important as part of the annual service to help maintain boiler efficiency and extend the life of the system.

This should be done whether the boiler has a stainless steel or aluminium heat exchanger. Although boilers with high-grade stainless steel heat exchangers, such as Potterton Commercial’s Siruis range, are less likely to react to contaminants in system water,

maintaining the quality of the water circulating through a heating system is essential no matter which material the heat exchanger is made from.

Modulation ratio

In addition to planned annual maintenance and servicing, choosing the right boiler in the first place should also form part of the strategy to reduce breakdowns and maximise the life of a heating system. This is where a boiler’s modulation range comes in; those with a higher ratio will cause less wear and tear on system components and work more efficiently.

Put simply, modulation range is the difference between the maximum and minimum output of a boiler. This is often expressed as a ratio e.g. 4:1; as a general rule, the higher the ratio, the better.  If a boiler has a narrow modulation ratio, the minimum output of the boiler will be higher than it needs to be, causing the boiler to constantly switch on and off. This wastes fuel and adds additional wear and tear to components. In contrast, a wider boiler modulation ratio reduces constant on/off cycling, therefore improving efficiency and extending the life of a boiler. 

Modulation ratio is important, as once a room has reached the desired temperature and thermostatic radiator valves (TRVs) are closed, the power demands on the boiler will be considerably lower. For example, the boiler will fire for longer and work harder in the morning to warm up classrooms to the desired temperature. As the rooms warm up, a boiler with a wide modulation ratio would enable the gas rate to be lowered gently, and the system can carry on operating on a lower output. Potterton Commercial’s Sirius two boilers have a modulation ratio of 9:1, so its 90kW model can modulate down to 10kW. This allows the system to tick over and maintain classrooms at a constant temperature in a more energy efficient way.

Putting in place a boiler with a higher modulation ratio alongside a regular maintenance regime can reduce wear and tear on a heating system. This in turn, can make annual servicing more straightforward and reduce the risk of costly breakdowns. With lower energy bills and a longer-lasting system also on the cards, it’s a no-brainer for any facilities manager who need to make the most of their school’s funds.

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