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SERVICING
excel HE -
Installation and Servicing
66 AIR PRESSURE SWITCH REPLACEMENT
1.
Refer to Frame 51.
2.
Remove the boiler front and left hand side
panel. Refer to Frame 44 and 45.
3.
Remove sensing pipe from air pressure
switch.
4.
Remove the two screws retaining the air
pressure switch.
5.
Remove electrical connections.
6.
Fit new air pressure switch and refit electrical
connections and sensing pipe.
7.
Re-assemble in reverse order, ensuring the
sensing pipe is replaced onto the top
connection marked "L".
8.
Check the operation of the boiler. Refer to
Frame 50 and 51.
67 DRAINING THE BOILER
1.
Refer to Frame 51.
2.
Close all the water isolating valves (CH and
DHW).
3.
To drain the central heating circuit, attach a
length of hose to the drain point and open the
drain valve.
Note.
Some residual water may be experienced
during the replacement of components.
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4.
As there is no direct drain for the domestic hot water
circuit, depending on the location of the boiler, opening
the lowest hot water tap may drain this circuit.
Note.
Some residual water may be experienced during
the replacement of components.
5. After replacing any component on the boiler, close
the drain valve, remove the hose and open all system
isolating valves (re-pressurise as appropriate)
before proceeding to check operation of the boiler.
6.
Check the operation of the boiler. Refer to Frame 50
and 51.
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