Rheem 090 Owner's Manual And Installation Instructions page 35

This water heater is intended to be permanently connected to the water mains
and not connected by a hose-set. A braided flexible hose or semi-flexible
connector may be used for connection to the water heater, where permitted by
AS/NZS 3500.4.
PIPE SIZES
To achieve true mains pressure operation, the cold water line to the water heater
should be the same size or bigger than the hot water line from the water heater.
The pipe sizing for hot water supply systems should be carried out by persons
competent to do so, choosing the most suitable pipe size for each individual
application. Reference to the technical specifications of the water heater and
local regulatory authority requirements must be made.
TEMPERATURE PRESSURE RELIEF VALVE
The temperature pressure relief valve is shipped behind the front cover. The
temperature pressure relief valve must be fitted before the water heater is
operated. Before fitting the relief valve, make sure the probe has not been bent.
Seal the thread with an approved thread sealant such as Teflon tape - never
hemp. Make sure the tape does not hang over the end of the thread.
Screw the valve into the correct opening
page 32) leaving the valve drain pointing downwards. Do not use a wrench on
the valve body - use the spanner flats provided. A copper drain line must be fitted
to the temperature pressure relief valve (refer to
The valve must be insulated with closed cell polymer insulation or similar
(minimum thickness 9 mm) and the insulation installed so as not to impede the
operation of the valve. The insulation must be weatherproof and UV resistant if
exposed.
EXPANSION CONTROL VALVE
Local regulations may make it mandatory to install an expansion control valve
(ECV) in the cold water line to the water heater. In other areas, an ECV is
required if the saturation index is greater than +0.4 (refer to
page 18).
The expansion control valve must always be installed after the non-return valve
and be the last valve installed prior to the water heater
page 34). A copper drain line must be fitted to the expansion control valve (refer
to "Relief Valve Drain"
The valve, if installed within 500 mm of the water heater, must be insulated with
closed cell polymer insulation or similar (minimum thickness 9 mm) and the
insulation installed so as not to impede the operation of the valve. The insulation
must be weatherproof and UV resistant if exposed.
on page 36).
35
CONNECTIONS – PLUMBING
(refer to the installation diagram
"Relief Valve Drain"
"Water Supplies"
(refer to diagram
on
on page 36).
on
on