With many businesses now restarting operations after months of closure, it is important for business owners to ensure the safety of their customers, visitors and staff. In particular, there is a significant risk of microbial contamination in water systems that have remained unused for long periods of time without the proper maintenance. Heating engineers are ideally placed to offer help, advice and improved customer service to businesses.

What are the risks?

Stagnant water in hot and cold water systems provides an ideal environment for bacteria to grow and thrive. There are a number of different types that may be present, but Legionella contamination is a particular concern. Legionella grows most effectively between 25°C and 45°C, and inhaling water droplets containing the bacteria can cause Legionnaires’ disease, a potentially fatal type of pneumonia. Therefore, all hot and cold water outlets, showers and any other fittings or equipment that create water spray or vapour are a potential source of the bacteria. Employers and those responsible for the premises have a legal responsibility to protect those using the building from Legionella under the Health and Safety at Work Act (HSW) and Control of Substances Hazardous to Health Regulations (COSHH).

This is an issue for any premises that have not been used due to COVID-19 restrictions but large buildings with long pipe runs and those with cold water storage tanks are at particular risk. This is due to the quantity of stagnated water that may be present. Also, older systems that have been modified or adapted throughout their life may contain areas of pipework, such as dead legs, where bacteria can grow more easily.

Some business owners may not be aware of these risks or may overlook the heating and water systems among the many other factors to consider when reopening. Therefore, heating engineers can provide significant value to customers by offering help and advice.

What can be done?

It is important for building owners and managers to look at the guidance offered by the Health and Safety Executive (HSE) and receive help from professionals in addressing any issues.

There are some simple steps that can be recommended to customers to help minimise the Legionella risk. Firstly, that every tap and outlet should be opened and allowed to run for several minutes. This will help to flush out any stagnant water that may have collected in pipework, cylinders and water tanks during the lockdown. It is essential for the person carrying out this task to adequately protect themselves from any exposure to the bacteria with the correct personal protective equipment (PPE), including a mask. It is particularly important when operating showers or spray taps as Legionella is easily transferred via a fine spray.

In terms of dealing with bacteria in the system, Legionella cannot survive temperatures over 60C so it is possible to decontaminate hot water systems through thermal pasteurisation. Among the most common approaches for cold water systems is chemical disinfection.

Furthermore, with the bacteria vulnerable to higher temperatures, it is essential to ensure that the building’s hot water system can heat and then store the water above 60C. The HSE also recommends that water is distributed at 50C or higher to prevent bacteria growth, so ensuring pipework is sufficiently insulated, especially on long pipe runs, is important. Similarly, below 20C Legionella bacteria are dormant. As such, insulating cold water pipes may also be advised to prevent the water temperature rising as it moves through the building.

However, it is worthwhile reminding customers that with minimal use over recent months there is an increased risk of issues with the system or even failure of appliances such as the boiler. Offering a package of checks, service and maintenance to these customers allows heating businesses to provide a value-added offering and help customers avoid issues that may delay reopening further.

With businesses needing to make up for lost trading during the pandemic it is important for them to get back up and running quickly, efficiently and safely. You can help your customers achieve this by offering specialist help, advice and services for their heating and hot water systems.