In-Service Testing
Purpose
The purpose of in service tests is to regularlymonitor and record the performanceof thethermostatic
mixing valve.
Deteriorationin performance can indicate the need for service workon the valveand /or water supplies.
Servicing Intervals
To reduce the buildup of lime scale and to ensure this shower works to its maximumperformance, we
recommend this shower isserviced every 6 –12 months depending on the hardness of your water.
Procedure
Using the same measuring equipment or equipment to the same specification as used in the
commissioning section, adjust the temperature of the mixed water in accordance with the manufactures
instructionsandthe requirement of the application, Carry outthe following sequence.
a)Record thetemperature of the hot and cold water supplies.
b)Record thetemperature of the mixedwater at the largest draw-off flow rate.
c)Record the temperature of the mixedwater at a smaller draw-off flow rate, which shall be measured. If
the mixed water temperature has changed significantly from the previous test results (e.g. >1K), record the
change andbefore re-adjustingthe mixedwater temperature check:
d)That any in-line or integral strainers areclean.
e) Anyin-line or integral check valvesor other anti-back siphonage devices are in goodworking order.
f) Any isolating valves are fullyopen.
With an acceptable mixed water temperature, complete the following procedure:
a)Record thetemperature of the hot and cold water supplies.
b)Record thetemperature of the mixedwater at the largest draw-off flow rate.
c)Record the temperature of the mixedwater at a smaller draw-off flow rate, which shall be measured.
d)Isolate the cold water supply to the mixing valveand monitor the mixed water temperature.
e)Record the maximumtemperature achieved as a result of(d)and the final stabilised temperature.
f)Record the equipment, thermometer etc. used for themeasurements.
If at step (e) the final mixed water temperature is greater than 41ºC and / or the maximum temperature
exceeds the corresponding value from the previous results by more than about 2K, the need for service
work is indicated.
Note: In-service tests should be carried out with a frequency, which identifies a need for service work
before an unsafe water temperature can result. Inthe absence of anyother instructionor guidance, the
procedure described in Annex Fof D 08 may be used.
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