mark on the body is between the two lugs on the cam.
• Refit the cap with the 40°C marking lining up with the index mark
on the body.
• Check that the cap moves between the maximum and minimum
marking.
Record the system conditions and valve settings so that they can be used
for valve maintenance.
MAINTENANCE
If water conditions or installation conditions are severe, and the valve is slug-
gish in operation, it is possible that there is a build up of scale within the
valve. the valve can then be stripped down and cleaned very easily.
1. Isolate the hot and cold supplies and remove the main body of the
valve from the installation.
2. Remove the control knob and cam.
3. Remove the headwork using a spanner. If using an adjustable
spanner ensure it is correctly adjusted to avoid damage to the head
work. The headwork can now be removed. (Fig 5)
4. The thermostatic element and piston can be lifted out. This leaves
the return spring, which can then also be lifted out. Ensure you note
the orientation of all the components so that they can be
re-assembled in the correct order.
5. With the spring removed the ‘O’ ring seal can be inspected,
cleaned and re-greased. If the ‘O’ ring is damaged it must be
replaced.
6. The components removed should be inspected and if any are
damaged they must be replaced.
7. Line strainers should be removed from the inlet fittings and rinsed
in clean water. The pipework should then be flushed to remove any
contamination that has fallen back down into the pipe.
8. If it is thought that cross flow is taking place, the check valves
should be removed from the inlet fittings, rinsed in clean water and
then replaced. The check valves can be removed by using a pair of
long nosed pliers, pulling them evenly on one of the fins. Do not
attempt to lever the check valves out, as this will damage them.
After cleaning and re-assembly, the valve should be reset and tested.