34
220683B
1 0 R e p l a c e m e n t o f P a r t s
CONTROL
KNOB
RETAINING
CLIP
SPLIT
GROMMET
Diagram 10.1
SHAKEPROOF
WASHERS AND
SCREWS
CONTROL
THERMOSTAT
ELECTRICAL
CONNECTIONS
BROWN
9
RED
8
PURPLE 7
YELLOW 6 & 3
LOCKNUT
ELECTRICAL
CONNECTIONS
4113
10 Replacement of Parts
Note. Replacement of parts must only be carried out by
a competent person.
Before replacing any parts isolate the boiler from the
electrical supply and turn the gas supply off at the gas
service cock, indicator slot should be vertical.
Unless state otherwise, all parts are replaced in the
reverse order to removal.
After replacing any parts always test for gas soundness
and if necessary carryout functional check of controls.
10.1 Access
Gain access as Section 8.1.
10.2 Control Thermostat/Pump Overrun -
diagram 10.1 and 10.2
Remove and support the electrical control box, refer to
Section 5.6.
Remove the control knob. Remove the electrical
connections from the thermostat body.
Release the thermostat body by unscrewing the two
screws and shakeproof washers in the front of the control
box.
Remove the split pin and withdraw the thermostat phial
from its pocket. Release the capillary from the base and
plastic retaining clip then remove it from the split
grommet. Release the capillary from its clips. Remove
the thermostat complete from the boiler.
Reassembly note. When fitting the thermostat, make
sure that the thermostat phial is covered with heat sink
compound then fully inserted into the phial pocket and
that the capillary is within the gland seal, see diagram
10.2. Remake the electrical connections. There must be
no kinks or sharp bends in the capillary.
10.3 Over Heat Cutoff Device - diagram
10.1, 10.2 and 10.2A
Remove and support the electrical control box, refer to
Section 5.6.
Remove the overheat cutoff electrical connections.
Disconnect the air pressure switch plug from the PCB.
Remove the locking nut from the overheat cutoff.
Release the capillary from the retaining clips then
remove it from the split grommet.
Remove the split pin and then the phial.
When refitting use the heat sink compound supplied.