10
f) record the equipment, thermometer etc. used for
the measurements
Table A: Guide to maximum stabilised tem-
peratures recorded during site tests
Application
Mixed water
temperature
Shower
43°C
Washbasin
43°C
Bath (44°C fill)
46°C
Bath (46°C fill)
48°C
The mixed water temperature at terminal fitting should
never exceed 46ºC.
If there is a residual flow during the commissioning or
the annual verification (cold water supply isolation test),
then this is acceptable providing the temperature of
the water seeping from the valve is no more than 2°C
above the designated maximum mixed water outlet
temperature setting of the valve.
Temperature readings should be taken at the normal
flow rate after allowing for the system to stabilise.
The sensing part of the thermometer probe must be fully
submerged in the water that is to be tested.
Any TMV that has been adjusted or serviced must be
re-commissioned and re-tested in accordance with the
manufacturers' instructions.
Commissioning and in-service
tests
Commissioning
Purpose
Since the installed supply conditions are likely to be
different from those applied in the laboratory tests it is
appropriate, at commissioning, to carry out some simple
checks and tests on each mixing valve to provide a
performance reference point for future in-service tests.
Procedure
1.
Check that:
a) the designation of the thermostatic mixing valve
matches the intended application
b) the supply pressures are within the range of ope-
rating pressures for the designation of the valve
c) the supply temperatures are within the range per-
mitted for the valve and by guidance information
on the prevention of legionella etc.
2.
Adjust the temperature of the mixed water in accor-
dance with the manufacturer’s instructions and the
requirement of the application and then carry out the
following sequence:
a) record the temperature of the hot and cold water
supplies
b) record the temperature of the mixed water at the
largest draw-off flow rate
c) record the temperature of the mixed water at a
smaller draw-off flow rate, which shall be measu-
red
d) isolate the cold water supply to the mixing valve
and monitor the mixed water temperature
e) record the maximum temperature achieved as a
result of (d) and the final stabilised temperature
NOTE: The final stabilised mixed water temperature
should not exceed the values in Table A.
