Guidance on Temperature Record Keeping

Temperature monitoring records for water outlets


The development of all pathogenic waterborne microorganisms depends on temperature. For example, Legionella is unable to breed in cold water below 20oC, and will quickly die at above 60oC levels. As such, we attempt to maintain hot and cold water in these temperature zones. It is important that water distribution temperatures are kept at less than 20oC for cold water and over 50oC for unmixed hot water     

If these temperatures are reached and there is adequate water turnover to avoid stagnation, there won't be any risk of Legionella bacteria.


Find the source for sentinels. 

Those are the first and last taps on a re-circulating mechanism for hot water supplies. For cold systems (or non-re-circulating hot water systems) these are the nearest and furthest taps from the holding tank. Other taps that are perceived to indicate a particular danger can also be sentinel taps.

Your schematic drawing and risk evaluation should include those details. If you are not sure which of the sentinel outlets are, please contact the Service Provider.

For either a single outlet or a group of hot water outlets, please use a different record sheet and type the number of outlets on the record sheet.


All channels should be checked within a 12-month span. If there are more than 12 outlets on a system, It is advised that more than one is checked monthly to ensure that all sources are verified in a 12-month span.

  • For scalding issues, outlet temperatures from point-of-use water heaters should not surpass 41oC
  • For legionella control, point-of-use heaters shall be set at 50oC. In
  • Buildings used by young children of nursery, persons with sensory impairment, or learning difficulties must be equipped with a TMV to a maximum temperature of 41oC.


Keeping a record of water temperature has become very easy these days. The most efficient method is to use a water temperature sensor to receive information in real-time and at much lower costs than traditional methods. The S1 water temperature sensor has a life span of 10 years and can be used to get the water temperature of your outlets at any time of the day.