Water Tank Inspection Before the Christmas Shutdown

For many commercial buildings across London, the Christmas period means a complete shutdown. Offices go dark, staff head home, and the building sits empty for anywhere from a few days to a couple of weeks. It is a well-earned break, but from a water hygiene perspective, it is also one of the riskier periods of the year.

When a building is unoccupied and water systems go unused, the conditions for Legionella growth can develop quickly. Cold water storage tanks that are not being turned over, pipework with no flow, and heating systems running on minimal settings all contribute to a situation that building managers and facilities teams should be thinking about before the holidays begin, not after.

This post sets out why the Christmas shutdown period poses a water hygiene risk, what a professional water tank inspection involves, and the steps worth taking before your building closes for the festive period.

What Happens to Water Systems During a Shutdown

In a typical working week, a commercial building uses water constantly. Taps, toilets, kitchens, showers and any other outlets all contribute to regular flow through the system. That daily movement of water is one of the simplest defences against Legionella development.

When the building shuts down for Christmas, that flow stops. Water sits in cold water storage tanks, in pipework, and in any dead legs or infrequently used outlets. Over several days, particularly if the building is cold, the temperature of that standing water can settle into the range between 20 and 45 degrees Celsius, which is exactly where Legionella bacteria are most likely to multiply.

The longer the shutdown, the greater the risk. A building that closes on the 20th of December and does not reopen until the 2nd of January has over two weeks of stagnation to deal with. If staff simply arrive back and begin using the building as normal, they may be drawing water through a system that has not been properly flushed or checked.

Why Cold Water Storage Tanks Need Attention

Cold water storage tanks are found in many commercial and older residential buildings across London. They are often located in roof spaces, plant rooms or utility areas, and in many buildings they are out of sight and out of mind for much of the year.

Before any extended shutdown, the tank should be checked. A professional inspection will look at the condition of the lid and any covers to confirm there is no debris or contamination entering the system. It will check for signs of corrosion, scale or sediment build-up, and assess whether the water temperature and turnover has been adequate in the period leading up to the closure.

If the inspection identifies any issues, a tank clean and disinfection before the shutdown is a far better outcome than discovering a problem in January when the building is back in full use. Our water tank cleaning service is available across London for commercial and residential properties of all sizes.

The Risk of Returning to a Stagnant System

One of the less considered risks around the Christmas shutdown is what happens when the building reopens. Staff arrive back, kettles go on, taps are used and showers run. If the system has been sitting stagnant for two weeks without any flushing or inspection, all of that first-use water has passed through pipework that may have developed a Legionella problem.

This is why a pre-return flush is important. Running all outlets for several minutes before the building is in normal use again flushes out standing water and replaces it with fresh water from the mains. For larger or more complex systems, a professional flush and, where necessary, a chlorination may be the more appropriate approach.

Our chlorination services cover commercial pipework, mains connections and storage tanks, and we can arrange emergency attendance for buildings that need to reopen quickly after the festive period.

ACOP L8 and Your Responsibilities as a Duty Holder

If you are responsible for a commercial building, whether as an owner, facilities manager or employer, you have a legal duty under ACOP L8 to manage the risk from Legionella in your water systems. That duty does not pause for Christmas.

Part of a proper water safety plan is accounting for periods of low use or vacancy, including planned shutdowns. That means having a procedure in place for what happens before the building closes, what monitoring or flushing takes place during the closure if it is extended, and what steps are taken before normal occupancy resumes.

If your building does not currently have a water safety plan or a recent Legionella risk assessment, the period before the Christmas shutdown is a practical time to address that. Our Legionella risk assessment service covers commercial and residential properties across London, with same-day assessments available where needed.

What to Arrange Before Your Building Closes

To summarise, here is what is worth organising before your commercial building shuts down for Christmas.

Book a water tank inspection if the tank has not been checked recently or if there is any concern about its condition. Arrange a Legionella risk assessment if one has not been carried out in the last twelve months or if the system has changed since the last assessment. Brief whoever is responsible for the building during the shutdown on the importance of not leaving the system completely dormant for an extended period. Plan a pre-return flush for when the building reopens, and consider a professional chlorination if the system is large or complex.

Taking these steps before you close is straightforward and relatively quick to arrange. Leaving them until January is a risk that is simply not worth taking.

If you would like to arrange a water tank inspection, a Legionella risk assessment or a chlorination service before your building closes for Christmas, contact our team at London Water Treatment. Call us on 020 4532 7773 or visit our water tanks page for full details of the services we provide.