andrews MAXXflo EVOCWH 120/302 Installation And Maintenance Manual page 65

CAUTION
Changing the following components will require some draining of the water system. It is essential
that all the air is removed from the heat exchanger before the heater is operated. To not do so may
damage the heat exchanger and invalidate the warranty.
6.2.13 HEAT EXCHANGER
• Turn off the water isolators located before and after the heat exchanger (see below):
Isolation valve
Isolation valve
• Drain water using the drain points to ensure the heat exchanger is as empty as possible.
• Disconnect all electrical connections to the fl ue, fl ow and return sensors.
• Disconnect the fl ue from the top of the heat exchanger by pushing the fl ue section upwards so that it
clears the heat exchanger
Return sensor connector
Flow sensor connector
• Disconnect the electrical connections to the ionisation probe, ignition probe, fan and gas valve and place
wiring to one side.
Ignition probe
Fan connectors
• Remove the air intake from the venturi by squeezing the spring clip together, and disconnect off set tube
Maintenance
Push assembly P
up p up u p u p u u p up u up u up u u p u u p up u upwards u p up up up u up u up u up up up up u u up u p u u u up p p
Ionisation probe Io
Gas valve G
connectors co o
65
Is Isolation valve
F Flue sensor connector
Sp Spring clip
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