Worcester 47 311 43, Инструкция по установке и обслуживанию

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14 Replacement Of Parts
1.1 IMPORTANT
Switch off the electricity and gas supplies before replacing any
components. After the replacement of any components, check
for gas soundness where relevant and carry out functional
checks as described in Section 11 - Commissioning
14.2 COMPONENT ACCESS
To replace components it is necessary to remove one or more
sections of the cabinet and cover plates within the appliance as
described in Section 13.3. The control assembly may also need
to be lowered as follows.
Remove the DHW flow/temperature selector knob. Remove the
four screws retaining the control assembly chassis to the main
boiler frame and unhook the chassis. Lower the chassis and re-
hook in the bottom of the large rectangular slots in the main
boiler frame (see fig. 28).
14.3 DRAINING THE APPLIANCE
Check that the electricity supply to the appliance is turned off.
Before removing any component holding water it is important
that as much water as possible is removed from the appliance.
(a) Central Heating Circuit. Turn off the central heating flow and
return valves at the appliance.
Remove the brass drain plug from the bottom of the pump inlet
manifold. Drain into a suitable container.
Some water may remain in the diverter valve, water to water
and Gas to Water heat exchangers and extra care must be taken
when removing these components.
(b) Domestic Hot Water Circuit. Turn off the mains cold supply
valve at the appliance and open the lowest hot water tap. A
quantity of water will remain in the Water to Water heat
exchanger and the diverter valve and extra care must be taken
when removing these components.
14.4 COMPONENT REPLACEMENT
1. Automatic Air Vent.
Remove the inner casing cover as described in Section 13.3
(a).
Drain the central heating circuit as described in Section 14.3
(a).
Unscrew the vent valve from the boss on the body of the
expansion tank.
Fit the replacement vent valve, making sure the joint to the
mounting boss is sound.
Open the valves and fill and re-pressurise the system as
described in Section 11.2.
2. Air Flow Pressure Switch.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel as described in Section 13.3
(a).
Carefully pull off the sensing tubes from the switch, noting the
position of the colour coded tubes.
Unscrew the single retaining screw and release the switch from
the internal boiler case. Remove the cover of the switch by
releasing the two screws and pull off the small spade terminals.
Fit the replacement switch in the reverse order ensuring that
the electrical connections have been made and that the sensing
tubes are fitted correctly.
3. Fan.
Check that the electricity supply to the appliance is turned off.
Remove the fan assembly as described in Section 13.3 (b).
Fit the replacement fan in the reverse order.
4. Gas to Water Heat Exchanger and Limit Thermostat.
Check that the electricity supply to the appliance is turned off.
Drain the central heating circuit as described in Section 14.3
(a). Remove the burner as described in 13.3(c). Lower the control
chassis as described in 14.2. Slacken the two union connections
on the flow and return pipe tails to the heat exchanger. Slacken
and lower the two locking nuts retaining the heat exchanger to
the inner casing base. Remove the two screws from the heat
exchanger top retaining plate and remove the plate. Lift up the
heat exchanger and remove forwards. Remove the limit stat
electrical connections located at the top RH side of the heat
exchanger. Undo the screw and remove the limit thermostat
retaining clip and thermostat body.
Fit the replacement heat exchanger in the reverse order ensuring
that both the face to face joint rings are correctly in the flow and
return connections.
Open the valves and fill and re-pressurise the system as
described in Section 11.2.
5. Water Flow Micro-switch
The water flow micro-switch is located under the water flow
regulator valve and can be removed and replaced as follows
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel as described in Section 13.3
(a).
Lower the control chassis as described in 13.2.
Remove the micro switch housing by slackening the three screws
holding the body together and releasing the housing from the
valve body. If required the wiring can be disconnected from the
spade terminals on the micro switch.
Replace the switch in reverse order and check the adjustment
of the switch as follows.
All hot water taps must be off.
With the appliance turned on electricaly remove the cover from
the adjustment opening and the adjustment screw. Turn the
screw in until the micro-switch operates (a click will be heard)
and continue turning for a further 1 to 1½ turns to reset the
micro-switch.
This adjustment must be carried out when the water flow valve
or any of its components have been disturbed.
6. Water Flow Regulator Valve
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel as described in Section 13.3
(a).
Drain the Domestic Hot Water circuit as described in Section
14.3 (b).
Lower the control chassis as described in 14.2.
Disconnect DHW inlet connection at the rear of the valve, pull
out the retaining clip from the outlet connection at the RH side
of the valve. Slacken the two valve retaining screws at the
connection to the gas valve and lower the regulating valve also
sliding out the ‘O’ ring jointed water outlet connection.
Remove the micro switch housing by slackening the three screws
holding the body together and releasing the housing from the
valve body. If required the wiring can be disconnected from the
spade terminals on the micro switch.
Fit the venturi to the new valve.
Fit the replacement water flow regulating valve in the reverse
order ensuring that both the face to face joint, seal and ‘O’ ring
seals are correctly positioned in the inlet and outlet connections.
Open the valves and fill and re-pressurise the system as
described in Section 11.2.
7. Gas Control Valve.
Turn off the main gas supply.
Remove the Water Flow Regulating Valve as described
preceding to gain clear access to the gas valve. Unplug the
electrical connection from the gas valve solenoid at the RH side
of the valve body. Undo the gas inlet at the rear of the valve.
Undo the union outlet connection at the top of the valve and
remove the valve.
Fit the replacement gas valve in reverse order ensuring that the