Maintenance; Maintenance Requirements; Check Cylinder Water Supply; Descaling Immersion Heaters - Heatrae Sadia ELECTROMAX Installation & Servicing Instructions Manual

8.0 Maintenance

8.1 Maintenance requirements

To e n s u r e t h e c o n t i n u e d o p t i m u m
performance of the Electromax it should be
regularly maintained. Maintenance should be
carried out by a competent person and any
replacement parts used should be authorized
Heatrae Sadia Electromax spare parts. It is
recommended that maintenance is carried
out annually and should include the checks
detailed in the sections below. The primary
system inhibitor concentration should also be
checked and topped up if necessary.
IMPORTANT: Disconnect ALL electrical
supplies before removing the covers or
panels to the appliance.

8.2 Check cylinder water supply

a. Turn off the mains water supply to the
Electromax and release the system
pressure by opening a hot tap. Some
hot water will flow for a short while, this
is normal.
b. Using an Allen Key unscrew the
four fixing screws on the Cold water
Combination Valve Pressure Reducing
Valve Housing (see Diagram 17, page
23). Remove the moulded housing.
c. Pull the Pressure Reducing Valve
Cartridge from the Housing. The
Strainer will be removed with the
Pressure Reducing Valve Cartridge.
Wash any particulate matter from the
Strainer mesh under clean running
water.
d. Replace the Pressure Reducing
Valve Cartridge in the Housing and
re-fit to the brass body of the Cold
Water Combination Valve. Secure
using the four Allen screws previously
removed.
e. Remove the dust cap from the top of the
Secondary Expansion Vessel. Check
the charge pressure of the Vessel using
a tyre pressure gauge. The pressure
(with system de-pressurised) should
be 3.5 bar. If lower than the required
setting it should be re-charged using
a tyre pump (Schrader valve type).
DO NOT over charge. Re-check the
charge pressure and when correct
replace the dust cap.

8.3 Descaling immersion heaters

In hard water areas where no water
treatment measures have been taken the
immersion heaters may require descaling.
The Electromax cylinder must be drained
before the immersion heaters can be
removed.
a. Disconnect the electrical supplies to
the Electromax.
b. Remove the front panels (refer to
section 3.2).
c. Connect a hose to the DHW drain
point (see Diagram 20) and unscrew
square headed stop plug to allow water
to drain from the cylinder. If water fails
to drain from the cylinder vent the unit
by manually opening the Temperature/
Pressure Relief Valve.
d. Remove the immersion heater covers
by unscrewing the securing screws.
Diagram 20 Drain Points
Filling Loop
Primary
System
Drain
Filling Loop
Connection
Isolating Valves
Installation & Servicing Instructions
Cylinder Drain
Connection
27