Potterton MULTIPOINT Installation And Service Instructions Manual page 16

Replacement of Parts - Page 16
Fig. 32
Fig. 33
WARNING: Keep the throttle body pointing away from your
face and body when you turn the screw. The spring
adjuster, spring and gland housing will eject from the body
with a lot of force. TAKE GREAT CARE.
Fig. 34
Re-Assemble as Follows:-
f. Feed the thermostat phial through the hole in the
chassis base. Re-fit the thermostat assembly and
spacer to the throttle body, ensure that the spacer is
correctly located between the thermostat flange and the
retaining plate and that the drain hole in the spacer is at
the bottom when relative to the whole appliance.
g. Ensure the 'O' ring is correctly seated within the
thermostat phial housing, carefully insert the phial
taking care not to disturb the 'O' ring. Re-fit the rubber
grommet around the capillary tube in the chassis base.
6.10. THROTTLE ASSEMBLY
a. Gain general access - see 6.2.
b. Drain the appliance - see 6.6.
c. Remove the thermostat assembly - see 6.9.
d. Release the feed pipe union nut.
e. Release the screw and plate securing the sensing tube
to the water governor.
f. Release the union nut securing the heating unit to the
throttle at the chassis base.
NOTE: When removing the throttle assembly, the
temperature selector spindle will disconnect itself from
the throttle body. On re-assembly the rod must be
positioned before the throttle is secured in place.
g. Remove the 2 screws securing the throttle to the
chassis base then remove the throttle.
DESCALE/ REGREASE & RECALIBRATE
h. Remove the 2 screws securing the retaining plate to the
throttle body.
i. Strip down the throttle assembly, descale and regrease
using a silicone grease such as Dow Corning 111.
Replace 'O' rings as necessary.
NOTE: Removal of the internal parts may be difficult
due to scaling etc, if necessary, remove the grub screw
from the rear of the throttle body and screw in one of
the long thermostat screws. This will force the internal
parts out. KEEP AWAY FROM FACE AND EYES.
j. On re-assembly, recalibrate the thermostat as follows:-
Re-fit the grub screw.
Turn temperature selector to '5'.
Open a hot water outlet.
Adjust the grub screw until water
temperature is between 55º - 58º C.