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The following procedures should be carried out after installation and every 12 months after to ensure that the
valve is functioning correctly.
Check that:
1. The application of the thermostatic valve matches the approved designation.
2. The supply pressures are within the recommended range for the application.
3. The supply temperatures are within the permitted range for the application and comply with the guidance
for prevention of Legionella.
4. The mixed temperature is as required for the application.
Record:
5. Each hot and cold supply. (Make a note of the measuring device used).
6. The mixed water temperature at the outlet device.
Isolate:
7. The cold supply to the mixing valve and record the mixed water temperature after about 5 seconds.
The temperature should not exceed the value given in table (2) below.
Note: 46 C is the maximum advised mixed water temperature from a bath tap. The maximum
temperature takes account of the allowable temperature tolerances inherent thermostatic mixing valves
and temperature loss in metal baths. It is not a safe bathing temperature for adults and children.
The British Burns Association recommends 37°C-37.5°C as a comfortable bathing temperature for
Children.
It should be noted in premises covered by the Care Standards Act 2000, the maximum mixed water
temperature is 43°C
°
Table 2 A guide to maximum temperature sets
Application Mixed water Advised maximum temperature
temperature rise during site testing
Shower 41 °C 43 °C
8
9
ADVISED COMMISSIONING & PERIODIC CHECKS
FREQUENCY OF REGULAR SERVICING
The purpose of servicing regularly is to monitor the performance of changes in system and valve set
up. This may require the need to adjust either the supply system or the valve. The A5322AA should
be checked and tested 12 months after commissioning.
Firstly measure the water temperature at the shower outlet.
Carry out the cold water supply isolation test by isolating the cold water supply to the TMV, wait for 5
seconds if water is still flowing check that the temperature is below 46C. If there is no significant
change to the set outlet temperature (+/-2ºC or less change from the original settings) and the fail-safe
shut off is functioning, then the valve is working correctly and no further service work is required.
Notes:
A residual flow is permitted during the commissioning or the annual verification (cold water supply
isolation test), then this is acceptable providing the water temperature is no more than 2ºC above the
designated outlet temperature.
Temperature readings should be taken at the normal flow rate after allowing for the system to stabilize.
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 should be re-commissioned and retested in accordance
with the instructions detailed above.
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