Heatrae Sadia ElectroMax Installation & Servicing Instructions Manual page 40

Expansion Vessel (see Diagram 44)
a. Drain primary circuit.
b. Unscrew union nut at connection
between the Expansion Vessel and
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
(see Diagram 45)
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 are of
different 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
Diagram 44 Primary Expansion Vessel
Removal
Primary Expansion
Vessel
Support
Nest
D i agr am 45 I m m er si on H eat erR em oval
Top El em ent Assem bl y
Bot t om El em ent
G asket
Assembly Difference
Backnut
Ther m ost at
I m m er si on
Heat er
Cover