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18
6.8
PRESSURE GAUGE (see fig. 20)
Carry out component removal procedure as de-
scribed in 6.4.
Remove pressure gauge locking screw, located
on manifold, and withdraw the pressure gauge
pipe, locate the spring tabs on the pressure
gauge body, push and hold tabs in, to enable
extraction of the gauge from its location.
Replace in the reverse order.
6.9
NTC THERMISTORS (temperature sensors)
Carry out component removal procedure as de-
scribed in 6.4.
Cold water inlet sensor (see fig. 21)
Disconnet thermistor electrical plug. Using a
13mm spanner slacken and remove the thermistor
and sealing washer.
Replace in the reverse order.
Flow & return sensors (see fig. 1 & 22)
Pull back protective boot and remove the 2 spade
connectors. Slacken and remove the 2 securing
screws.
Replace in the reverse order.
6.10
PRINTED CIRCUIT BOARD (PCB) (see fig. 23)
Carry out component removal procedure as de-
scribed in 6.4.
●
Locate and remove the 4 screws that secure
the PCB housing cover, then remove cover.
●
After carefully taking note of all wiring
connections, disconnect all wiring from the
PCB.
●
Locate and remove the PCB housing securing
screws, remove PCB housing.
●
Remove the 4 screws that secure the
transformer to the PCB housing.
●
Locate and remove the 3 screws that secure
the PCB to the housing.
Replace in the reverse order.
6.11
GAS VALVE (see fig. 24)
Carry out component removal procedure as de-
scribed in 6.4.
The gas valve must be changed as complete unit.
Unclip and remove the air chamber cover.
Disconnect the electrical plug from the gas valve.
Disconnect silicone tube from gas valve regulator.
Slacken and unscrew gas valve inlet and outlet
connections. Please note, the sealing washers
must be discarded and replaced with new sealing
washers. The gas valve can now be removed.
Replace in the reverse order. Refer to section
seven for detailed instructions on how to set-up
the gas valve. WARNING, A GAS SOUNDNESS
CHECK MUST BE CARRIED OUT.
Fig. 22
Fig. 23
Fig. 21
Cold water
inlet sensor
Actuator
locking pin
Actuator
Housing
P.C.B.
Cover
Fig. 20
Manifold
Screw
Screw
Pressure gauge
connection
Locking screw