Thermistor; Ignition Control Box; Driver Pcb; Pump 8. 1 - Sime benchmark FRIENDLY FORMAT Installation And Servicing Instrucnions

– Replace the thermostat and spread heat sink compound
(supplied) over the base of the new one.
– Re-assemble in reverse order. (Polarity is immaterial).
8. 1 0

THERMISTOR

The thermistor is clipped to the flow pipe below the overheat
thermostat.
The thermistor does not penetrate the waterways, therefore
it is not necessary to drain the appliance.
– Remove the casing front panel as described in section 5. 1 .
– Remove the thermistor securing clip from the pipe.
– Pull off the thermistor connection plug, and release the
thermistor from the clip.
– Replace the thermistor and re-assemble in reverse order
using the heat sink compound supplied.
TABLE 9
Temperature (°C)
20
30
35
40
45
50
55
60
70
80
8. 1 1

IGNITION CONTROL BOX

– Remove the casing front panel as described in section 5. 1 .
– Unscrew the single screw securing the plastic ignition
control box to the gas valve and pull off the control box in
a forwards direction.
– Unscrew the single screw securing the plastic control box
cover to reveal the electrical connections.
– Transfer the electrical connectors and wires etc to the
new PCB and re-assemble in reverse order.
8. 1 2

DRIVER PCB

– Remove the casing front panel as described in section 5. 1 .
– Pivot the control box downwards, by removing the two
screws.
– 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 potentiometer knobs.
– Release the PCB (four screws), transfer all connections
onto the new PCB, and re-assemble in reverse order.
– Re-set the CH burner pressure as described in section 4.3.
8. 1 3 PUMP
– Remove the casing front panel as described in section 5. 1 .
– Unplug the electrical connection plug.
– Isolate the C.H. flow and return valves (17 - 18 fig. 2), and
drain the appliance through the drain plug (13 fig 2).
– Unscrew both union connections.
– Replace the pump, and re-assemble in reverse order,
using the new gaskets supplied with the pump. If the new
pump is fitted with a speed adjuster, ensure that the
speed is set to maximum.
– Refill and commission the system as described in section 4. 1 .
8. 1 4
– Remove the casing front panel as described in section 5. 1 .
– Remove the gas valve (to improve access) as described in
section 8.6.
– Isolate the C.H. flow and return valves, and the D.H.W. iso-
lation valve (17 - 18 - 19 fig. 2).
– Drain the appliance through the drain plug (13 fig 2).
– Drain the D.H.W. circuit by opening any D.H.W. tap below
the level of the boiler.
– Remove the two screws pivot the control box downwards.
– Disconnect all union connections to the D.H.W. heat
Resistance (Ω)
exchanger and remove the heat exchanger.
12,764
– Fit new heat exchanger and re-assemble in reverse order
8,579
using the new gaskets supplied with the heat exchanger.
7, 1 02
– Refill and re-commission the system as described in sec-
5,915
tion 4. 1 .
4,955
4, 1 73
3,533
8. 1 5
3,006
2,208
– Remove the casing front panel as described in section 5. 1 .
1,650
– Remove the gas valve (to improve access) as described in
section 8.6.
– Isolate the C.H. flow and return valves, and the D.H.W. iso-
lation valve (17 - 18 - 19 fig. 2).
– Drain the appliance through the drain plug (13 fig 2)
– Drain the D.H.W. circuit by opening any D.H.W. tap below
the level of the boiler.
– Remove the two screws pivot the control box downwards.
– Disconnect all union connections from the divertor valve.
Withdraw the valve and remove the circlip securing the
microswitch assembly.
– Transfer the electrical connections onto the new valve. If
necessary. refer to the wiring diagrams in section 7.
– Re-assemble in reverse order, using the new gaskets sup-
plied with the valve.
– Refill and re-commission the system as described in sec-
tion 4. 1 .
8. 1 6
– Remove the casing front panel as described in section 5. 1 .
– Remove the two screws pivot the control box downwards.
– Pull out t he micr oswitch cir clip, and lif t of f t he
microswitch assembly.
– Transfer the electrical connections ont o the new
microswitch assembly. If necessary. refer to the wiring
diagrams in section 7.
– Re-assemble in reverse order.
8. 1 7
In the unlikely event of failure of the expansion vessel
diaphragm it is acceptable to leave the vessel in position

D.H.W. HEAT EXCHANGER

DIVERTOR VALVE - COMPLETE

DIVERTOR VALVE - MICROSWITCH ASSEMBLY

C.H. EXPANSION VESSEL

25