25
2000225229C
CONTROL
KNOB
Diagram 10.3
EXTENSION
PIECE
P.C.B.
SUPPORT
P.C.B. FUSE
12006
Diagram 10.2
Diagram 10.1
THERMISTOR
P.C.B.
CONNECTION
12281
SAFETY
TEMPERATURE
LIMITER
ELECTRICAL
CONNECTORS
THERMISTOR
PHIAL
10 Replacement of Parts
SECURING
GROMMET
SECURING
SCREW
10272
IMPORTANT NOTES
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, see
diagram 6.2.
Unless stated 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 5.2.
10.2 Electrical Thermistor, Part No. 2000458914
Slacken control box securing screw and swing out the control
box, see diagram 5.9.
Disconnect the thermistor plug from the control board by slightly
bending the retaining latch and removing the plug, see diagram
10.1.
Remove fan assembly, see section 5.3.
Remove the plastic R clips which retain all leads at the rear of
boiler.
Carefully pull out the securing grommet and withdraw the
electrical thermistor from its phial, see diagram 10.2.
Remove thermistor lead from the plastic R clips at rear of case
and the cable clips (these are located down left hand side of
boiler).
Draw thermistor lead followed by thermistor out through the case
grommet.
Re-assembly
NOTE:
When fitting the electrical thermistor make
sure that the thermistor and grommet are fully inserted into the
phial, see diagram 10.2. Take care when re-threading as not to
damage thermistor.
Refit the cable clips and the plastic R clips retaining the leads.
Refit the plastic retaining tag.
Refit the thermistor lead plug.
Refit fan assembly.
IMPORTANT: Where the flue has a rear connection (from
back of casing), see diagram 5.6, it is essential to make
certain that the flue duct is fully located into the fan elbow
until it can go no further, enabling the flue duct to make a
complete seal when secured.
10.3 Safety Temperature Limiter, Part No.
227038 - diagram 10.2
Gain Access as Section 5.2.
Remove air pressure switch, see diagram 10.6.
Remove the electrical connections from the safety temperature
limiter device, see diagram 10.2.
Undo retaining bracket screw and remove together with safety
temperature limiter.
When refitting use the heat sink compound provided
Re-assembly
NOTE:
Check that safety temperature limiter is
secure.
NOTE:
Polarity of electrical connections is not important.
RETAINING
BRACKET
P.C.B.
ELECTRICAL
THERMISTOR