Mira FORM Installation & User Manual page 34

Maintenance Procedure - Thermostatic Cartridge
Removal
1. Turn off the supplies to the shower control. Open the flow control to release the
trapped water pressure and assist the draining of residual water.
2. Remove the temperature and flow knob assemblies, using the 2.5 mm A/F
hexagonal wrench (supplied). Remove the concealing plate, seals and support
bracket. Do not remove the temperature spindle.
3. With the removal clip still in place, unscrew the head nut using a 35 mm A/F
wrench. This will release the body shroud and also begin to draw the thermostatic
cartridge out of the shower control body.
Caution! Some residual water may be released.
4. Note which inlet aligns with the hot (marked H and coloured red) lug on cartridge.
5. Pull the thermostatic cartridge free of the shower control body.
Cleaning/Renewal of Parts
6. The interior surface of the shower control body must be clean before refitting the
cartridge. If scale or deposition is present, clean (without thermostatic, flow
and checkvalve cartridges fitted) using a mild proprietary inhibited scale solvent,
e.g. domestic kettle descalent. After descaling, rinse the body thoroughly in
clean water before refitting cartridges.
Note! The body interior must be cleaned carefully and not damaged in any way.
Do not use any abrasive material.
7. Cartridges may only be cleaned by flushing through under a jet of clean water to
remove lodged particles. Do not descale. Cartridges are not serviceable, and
must not be dismantled.
Cartridges cannot be tested individually, service condition should be assessed
as part of the performance check; refer to Commissioning Checks.
8. When renewing the thermostatic cartridge, retain the temperature spindle, removal
clip and head nut off the displaced unit and refit.
9. Examine all accessible seals for signs of deformation or damage, and renew as
necessary, taking care not to damage seal grooves (a Service Pack is available,
containing all seals and strainer screens that may be necessary for renewal
during maintenance or servicing).
10. Lightly coat all rubber seals with a silicone-only based lubricant to assist
reassembling (see lubricants).
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