25
tion union.
– Remove the screw securing the expansion vessel bracket
at the top, rear of the appliance.
– If a rear flue outlet is used it is necessary to disengage the
flue and air duct temporarily. Refer to section 3.5.
– Remove the adjusting screws on the wall mounting bracket there-
by allowing the appliance to move slightly forwards at the top.
– Lift the expansion vessel out of the appliance through the top.
– Replace the expansion vessel and re-assemble in reverse
order. Re-pressurise and re-commission the system as
described in section 4.1.
8.18
PRESSURE GAUGE
– Remove the casing front panel as described in section 5.1.
– Remove the two screws and pivot the control box downwards.
– Isolate the C.H. flow and return valves (17 - 18 fig. 2).
– Drain the appliance through the drain point (13 fig. 2).
– Unscrew the pressure sensor from the brass body near
the drain point.
– Squeeze the gauge to depress the retaining clips, then
ease the gauge forwards.
– Reassemble in reverse order. Refill and re-commission the
system as described in section 4.1.
8.19
SAFETY VALVE
– Remove the casing front panel as described in section 5.1.
– Remove the two screws and pivot the control box down-
wards.
– Isolate the C.H. flow and return valves (17 - 18 fig. 2).
– Drain the appliance through the drain point (13 fig. 2)
– Unscrew the union supporting the outlet pipe from the
valve, and remove the valve by unscrewing it from the
brass housing.
– Fit the new safety valve using a suitable jointing compound
and re-assemble in reverse order. Refill and re-commission
the system as described in section 4.1.
8.20
AUTOMATIC AIR VENT
– Remove the casing front panel as described in section 5.1.
– Isolate the C.H. flow and return valves (17 - 18 fig. 2).
– Drain the appliance through the drain point (13 fig. 2).
– Unscrew the automatic air vent.
– Fit the new automatic air vent using a suitable jointing com-
pound and re-assemble in reverse order. Refill and re-com-
mission the system as described in section 4.1.
8.21
TIME CLOCK
– Remove the casing front panel as described in section 5.1.
– Remove the two screws and pivot the control box downwards.
– Open the plastic driver control box housing by removing the
room thermostat cover (one screw) and the single central
fixing screw then prising open the four locating tabs.
– Pull off the electrical connections at the back of the clock.
– Remove the four screws securing the plastic frame of the
time clock to the fascia panel.
– Remove the plastic frame and pull out the time clock.
– Re-assemble in reverse order and test the operation of
the new clock.
Set it to the desired settings as described in section 4.3
Position Code
Description
1
6150700
Divertor valve microswitch
2
6219701
Cap MPMV 3310 for microswitch
3
6223800
Washer MPMV 3318
4
6220601
O-ring R1 MPMV 3325
5
6218500
Clip Ø 17 for diverting valve
6
6153101
Diaphragm assembly for divertor valve
Position Code
Description
7
6231201
Brass ring nut MPMV 3320
8
6223902
Teflon short spacer MPMV 3315
9
6222000
D.H.W. filter MPMV 3326
10
6220602
O-ring 4093 MPMV 18
11
6223903
Teflon long spacer MPMV 3316
12
6153401
Snap ring J26 MPMV 3323
9.1
DIVERTOR VALVE
Fig. 29
9
EXPLODED VIEWS