Legionella control in hotel water systems: temperatures, flushing and records

Legionella control in hotels means keeping hot water hot and cold water moving, running the taps in rooms nobody is using, cleaning tanks and shower heads on schedule, and writing all of it down. Türkiye's Ministry of Health regulates this area, and the duty covers temperatures, flushing and records. Regulations change: confirm the current thresholds, reporting deadlines and penalties with your provincial health directorate and legal counsel before you change your protocols.

A wing closes for three weeks in low season. On the day it reopens, a guest turns on the shower in room 214 and the water runs warm, then lukewarm. Nothing in the room is broken. The problem started three weeks earlier, in water that stood still. After reading this article you will know which temperatures to hold, which rooms to flush and how often, what to do before reopening, and which records an inspector will ask to see.

Where does legionella risk sit in a hotel water system?#

In warm water that is not moving. A hotel has more of that than most buildings: long pipe runs to distant wings, dead legs left after a refurbishment, rooms empty for days, cooling towers, spa pools and decorative water features.

The exposure route is aerosol, not a glass of water. A shower, a spa jet or a cooling tower plume can carry the bacteria into the lungs, which is why the outlets and the towers matter more than the water in the kitchen. The Ministry of Health's Regulation on the Procedures and Principles for Controlling Legionnaires' Disease (opens in a new tab) (Resmî Gazete, 13 May 2015, No. 29354) applies its routine preventive measures to tourist accommodation such as hotels, motels, holiday villages and guesthouses (Article 5).

Start with a drawn map of the water system: every tank, water heater, riser, floor, outlet group, cooling tower and spa pool, with the valve that isolates each section. Mark the low-use points on the same map: rooms out of order, a wing closed for the season, the staff shower in a back corridor, a garden tap nobody opens.

Walk the map once a season with maintenance and housekeeping in the same room. The person who knows which rooms are empty is rarely the person who knows which valve closes a riser. The map is not decoration: Article 6 makes a water management plan and regular records a duty, and the map is the first page of it. For how this fits the wider maintenance calendar, see our article on the hotel preventive maintenance plan.

What water temperatures does the regulation require?#

Hot water at 60°C or above in the tanks, 50°C or above on return, and 50 to 60°C at the tap or shower head within one minute of running, measured every day while the facility operates (Article 8(1)).

Measure at the outlet, not at the boiler panel. The reading that matters is what reaches the guest's shower within that first minute. Record it with the point, the date, the time and the initials: a temperature without a location and a date proves nothing to an inspector.

The 60 and 50 pair is a storage-and-return rule. The tank must be hot enough to kill bacteria, and the water returning must be hot enough that the loop never cools into the range where bacteria multiply. Where a distant leg cannot reach 50°C within a minute, that is a finding for the water management plan: rebalance the loop, insulate, or shorten the run. Do not write the number down as if it passed.

Cleaning is on a calendar, not on a feeling. Cold-water tanks are drained, cleaned and disinfected at least twice a year, hot-water tanks at least three times a year. Shower heads and tap filters are physical: sediment is cleaned out monthly and they are disinfected weekly.

How do you flush rooms that have not been used for a week?#

You do not wait for the week to pass. The regulation asks for the taps and shower heads in unused rooms to be run with hot and cold water for 3 to 5 minutes every day, so a room is never left standing long enough to need a rescue.

Define "unused" in writing, for example a room where no water has been drawn in the last 24 hours. Out-of-order rooms, blocked rooms, a closed wing and low-season floors all count. Make it a housekeeping task with a line in the round: room number, time, initials, and the hot-water reading if your plan asks for one.

Three to five minutes with both hot and cold running, not a ten-second rinse. The point is to replace the water standing in the branch pipe, not to wet the tray. Sequence it with room status: flush before the room is cleaned and returned to sale, so a flushed room is not mistaken for a finished one.

Give the person flushing a way to escalate. A shower that runs lukewarm in a room flushed yesterday is a work order, not a note in a notebook, and our article on hotel maintenance work orders covers how to close that loop. If a hot-water tank or part of the hot-water system itself has been out of use for a week or more for maintenance, the water is kept above 70°C for at least one day from the moment it is back in use.

What must a hotel do before reopening after a closure?#

Five things, in order, before the first guest checks in: heat the tanks, run every hot outlet, treat the whole system chemically, descale the outlets, and clean the cooling towers (Article 8(2)).

Raise all hot-water tanks to 70°C and hold them there for at least 24 hours. Run all hot taps and shower heads for at least 5 to 10 minutes so the water reaches at least 60°C, and keep tap water above 60°C for at least 24 hours. Hyperchlorinate the whole hot and cold system to at least 3 ppm residual chlorine for at least 24 hours, or use another chemical eradication method.

Then clean and descale shower heads and taps, and empty, clean and disinfect the cooling towers. Keep the sequence: raise the tanks, run every hot outlet, treat the system, descale the outlets, clean the towers. A shower head cleaned before the system is treated gets cleaned twice. If your hotel treats the system before flushing the outlets, say so plainly: that is your own practice, not the regulation's sequence. Sign the reopening as a dated checklist with times, not as a memory of what the team usually does. Our checklist for closing a seasonal hotel for winter covers the other end of the same season.

Who takes water samples, and what happens after a case is notified?#

The routine duties are temperatures, flushing and cleaning. Sampling becomes a formal, timed duty when a travel-associated case is notified, and the accommodation pays for the samples taken for environmental surveillance.

The Ministry of Health is a member of the European Legionnaires' Disease Surveillance Network (ELDSNet), through which travel-associated cases linked to Türkiye are reported, according to the Ministry's Legionnaires' Disease Control Programme Guide (opens in a new tab) (Türkiye Halk Sağlığı Kurumu, 2016). ELDSNet sends the case details, with the accommodation's name and the length of stay, to the country of travel so an environmental investigation can be made. The notification calls for an investigation; it does not mean the case came from that accommodation.

Within 10 days of a notification, the provincial directorate's preliminary report, the water-system risk assessment form, the water sample records and the first sampling results must reach the Ministry's communicable diseases department in Ankara. Within 30 days, the final report, the routine-control checklist and undertaking signed by the facility, and the second sampling results must reach the same department.

The guide defines a single case as one case at an accommodation within two years, a cluster as two or more within two years, and a rapidly developing cluster as three or more within three months. The consequences are practical: a case-linked accommodation is inspected every two months for two years even if samples after decontamination are negative, and if the necessary work at a cluster accommodation is not done and its adequacy cannot be shown, ELDSNet publishes the accommodation's name. Agree the sampling procedure with the provincial directorate and the laboratory before the first sample, not during an investigation. The trained staff member named to the directorate is the natural person to take it.

Which records does an inspector ask for?#

The water management plan, the routine records behind it, and the name of one trained staff member notified to the provincial directorate. Article 8(3) requires the file to be shown to the directorate or inspectors on request.

The trained person must be educated to at least high-school level, have taken at least 8 hours of Legionella training from the directorate, and have their name notified to the directorate (Article 7). Name a deputy as well, or the duty leaves with the person on annual leave. The file holds the plan and the map, the daily temperature log, the flushing log, tank cleaning and disinfection dates, shower head and filter cleaning, chemical treatment records, sampling results, training records and the risk assessment form. Keep it where the person on shift can reach it at three in the morning, not on a manager's laptop.

A breach falls under the administrative sanction in Article 282 of Public Health Law No. 1593 (Article 27). Confirm your own position, dates and amounts with a legal adviser. The same file answers a tour operator's audit and a guest's question, which is why it is worth building once and keeping current.

What to do next#

Draw the water system map this week, mark the low-use points on it, and start the daily temperature and flushing logs the same day. Everything else in this article hangs on those two records: the temperatures tell you whether the system is working, the flushing log tells you whether the empty rooms are being looked after, and together they are the file an inspector or a tour operator will ask to see.