22
6.6
SAFETY VALVE (fig. 26)
Carry out component removal procedure as de-
scribed in 6.4. Disconnect the outlet pipe
(A)
from
the safety valve, remove safety valve locking pin
(B)
from the hydraulic manifold. Replace in the
reverse order.
6.7
BOTTOM AUTOMATIC AIR RELEASE VALVES
(fig. 25)
Carry out component removal procedure as de-
scribed in 6.4.
Remove the expansion pipe locking pin
(D)
from
the pump assembly and remove the expansion
pipe. Locate and remove the AAV locking pin
(G)
from the pump assembly and remove the AAV
assembly
(H)
. Replace in the reverse order.
6.7.1
TOP AAV (fig. 27)
Carry out component removal procedure as de-
scribed in 6.4.
Remove the drain pipe
(A)
. Unscrew the top AAV.
Replace in the reverse order. White Loctite is
necessary to fix the AAV.
6.8
WATER PRESSURE SENSOR/GAUGE (fig. 26)
Carry out component removal procedure as de-
scribed in 6.4.
Locate and remove the locking pin
(C)
from the water
pressure sensor/gauge assembly
(D)
. Remove the
wiring. Carefully withdraw the assembly.
Replace in the reverse order.
6.9
PRIMARY THERMISTOR (fig. 1)
Carry out component removal procedure as de-
scribed in 6.4.
Unclip and remove the air chamber front cover.
Unclip the primary thermistor from the flow outlet
pipe. Disconnect thermistor electrical plug.
Replace in the reverse order.
6.10
RETURN THERMISTOR (fig. 1)
Carry out component removal procedure as de-
scribed in 6.4.
Unclip and remove the air chamber front cover.
Unclip the return thermistor from the return inlet
pipe. Disconnect thermistor electrical plug.
Replace in the reverse order.
6.11
PRINTED CIRCUIT BOARD (fig. 28)
Carry out component removal procedure as de-
scribed in 6.4.
Lift the control fascia upward and rotate it.
Locate and remove the screws
(A)
which secure
the PCB cover, push the clips
(B)
and remove
cover, after carefully taking note of all wiring
connections, disconnect all wiring from the PCB,
locate and remove the PCB securing screws,
remove the required PCB.
Replace in the reverse order.
6.12
GAS VALVE(fig. 14 & 29)
Carry out component removal procedure as de-
scribed in 6.4.
The gas valve must be changed as complete unit.
Disconnect the electrical plug and leads from the
gas valve, lacken and unscrew gas valve inlet
(A,
fig. 14)
and outlet
(A, fig. 29)
connections.
Please
note,
the sealing washers
(B)
must be discarded
and replaced with new sealing washers. Discon-
nect the compensation pipe
(C)
. Locate and re-
move gas valve retaining screws
(D)
on the under-
side of the boiler if required, the gas valve can now
be removed. Replace in the reverse order. Check
and adjust burner pressure settings.
WARNING, A GAS SOUNDNESS CHECK MUST
BE CARRIED OUT.
Fig. 28
A
B
Fig. 29
Fig. 27
A
B
C
D
A
F
B
E
D
F
A
B
C
E
H
Fig. 26
G
I
