Heatrae Sadia Express 50 Litres, Installation, Operation And Maintenance Manual

Page: 15 / 24

15
9. Maintenance
9.1 Standard inspection & maintenance
operations
To ensure the continued safe and efficient operation of
the appliance, it should be regularly maintained.
Maintenance should be carried out by a competent
person and any replacement parts used should be
authorised Heatrae Sadia spare parts.
It is recommended that maintenance is carried out
annually and should include the checks detailed in the
section below.
In hard water areas the appliance will require periodic
descaling to ensure efficient operation. To descale the
appliance:
Descaling immersion heater
CAUTION
Be careful when removing the immersion
heater as some water will be left in bottom
of appliance.
DO NOT use a sharp implement as damage
to the element surface could be caused.
DO NOT scrape element clean.
�
Turn off the cold water supply and isolate the
electrical supply to the appliance.
�
Attach a hosepipe to the drain cock having sufficient
length to take water to a suitable discharge point
below the level of the appliance.
�
Open a hot tap close to the appliance (cistern fed
installations) and open drain cock to drain the
appliance.
�
When empty, open the cover to the immersion
heater housing. Remove the securing screw then
release the cover by carefully inserting a flat bladed
screwdriver into the slots around the cover and
gently levering outwards until the catches release
(see Figure 9, page 15).
�
Disconnect wiring from immersion heater terminals.
�
Carefully remove the thermostat and thermal cut-out
capilliary sensors from the pocket on the immersion
heater.
�
Place a suitable receptacle beneath the immersion
heater to collect any water left in the appliance.
�
Unscrew immersion heater bolts and remove
immersion heater from the water heater.
NOTE: Over time the immersion heater gasket may
become stuck to the mating surface. To break the seal
there is a seperate threaded hole in the plate. Screw
one of the removed bolts into this hole to help remove
element.
�
Carefully remove any scale from the surface of
the element. Remove any loose scale from the
appliance interior.
�
Ensure sealing surfaces are clean and seals are
undamaged, if in doubt fit a new gasket.
�
Replace immersion heater ensuring correct
orientation. One of the bolt holes uses a larger bolt
to ensure the correct orientation.
�
Tighten bolts.
�
Fill appliance with water and check for leaks.
�
Replace thermostat and thermal cut-out capillary
sensors into pocket on the immersion heater,
ensure that the thermostat is inserted first followed
by the cut-out (see figure 2, page 7 to identify).
Ensure they are pushed fully into the pocket and
the capillary tubes are not kinked or damaged.
�
Reconnect wires from the thermostat onto element,
ensuring that the terminals are correctly engaged.
�
Reconnect the earth wires to the earth stud.
�
Refill the appliance. When water issues from the
hot tap or spout allow to run for a short while to
purge any air and flush through the pipework.
Open successive hot taps served by the appliance
to purge any air. With all hot outlets closed check
all joints for leaks.
�
Close immersion heater housing cover ensuring
the catches are pushed fully home until they
"snap" into place. Secure by replacing the screw
previously removed.
Figure 10: Cover removal