9
TMV3 ART 33 Screwed Rev 1
outlet temperature setting of the valve.
•
If a water supply is fed by gravity then the supply pressure should be verified to ensure the
conditions of use are appropriate for the valve.
•
The fitting of isolation valves is required as close as is practicable to the water supply
inlets of the thermostatic mixing valve.
•
Temperature readings should be taken at the normal flow rate after allowing 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 must be re-
commissioned and re-tested in accordance with the manufacturer’s instructions.
•
In the absence of any other instruction or guidance, it is recommended that In-service
Tests are carried out once every 6 months as a minimum.
9.
TMV Cleaning Instructions
•
Most domestic water supplies contain calcium which will separate out when the water is
heated in a system. The degree and speed of scaling may vary depending on factors such
as water flow rates, system design, the hardness of the water and the temperature to
which the water is heated.
•
Deposits of scale may over time form in the valve, particularly at the hot inlet. The
formation of the scale may adversely affect the performance of the valve which will be
detected during the in-service testing. If this occurs it will be necessary to remove
the valve for de-scaling and service.
Cleaning Procedure
•
Isolate the hot and cold supply.
•
Remove the valve to a clean working area.
•
Remove the protective cap.
•
Unscrew the headwork of the valve.
•
Carefully remove the temperature sensitive thermal element and piston assembly and put
to one side.
•
Remove the main spring and flow guide and carefully put to one side.
•
Inspect the components for contamination or damage.
