Heatrae Sadia ELECTROMAX Installation & Servicing Instructions Manual page 40

9.3.8 Removing
Expansion Vessel (see diagram 44, page
40)
(a) Drain primary circuit.
(b) Unscrew union nut at connection between
the expansion vessel and the flexible hose
coupling.
(c) Lift expansion vessel from moulded
support nest. Note: the expansion vessel
may contain some water, take care not to
spill this into the product by lifting from
the connection end of the vessel.
(d) Replacement is a reversal of the above
procedure. Ensure vessel is inserted into
support nest the correct way up with the
air valve towards the top. Ensure sealing
washer is correctly fitted.
9.3.9 Removing the Immersion Heaters (see
diagram 45, page 40)
(a) Drain DHW cylinder.
(b) Remove the immersion heater covers by
unscrewing the securing screws.
(c) Disconnect the wiring from the immersion
heater thermostats. Remove thermostats
by carefully pulling outwards from the
heaters.
(d) Unscrew immersion heater backnuts using
the key spanner supplied with the unit.
Remove the immersion heaters. Over time
the immersion heater gaskets may become
stuck to the mating surface, to break the
seal insert a round bladed screwdriver
into one of the pockets on the immersion
heater and gently lever up and down.
(e) Replacement is a reversal of the above
procedure. Note: the upper and lower
immersion heaters
configurations. The "right angled" element
version should be used in the lower
immersion heater boss, the "straight"
element version should be used in the
upper immersion heater boss. Ensure the
"right angled" element is inserted into the
lower boss so the element hangs vertically
downwards towards the base of the unit.
40 Installation & Servicing Instructions
the Primary System
are of different
Primary Expansion
Vessel
Support
Nest
Diagram 44 Primary Expansion Vessel Removal
Top Element Assembly
Bottom Element
Gasket
Assembly Difference
Diagram 45 Immersion Heater Removal
Backnut
Thermostat
Immersion
Heater
Cover