Rheem 491 Owner's Manual And Installation Instructions page 12

ABOUT YOUR WATER HEATER
PRECAUTIONS
Where damage to property can occur in the event of the water heater leaking,
the water heater must be installed in a safe tray. Construction, installation and
draining of a safe tray must comply with AS/NZS 3500.4 and all local codes and
regulatory authority requirements. The safe tray must also meet the
requirements of Clause G12 of the New Zealand Building Code. AS/NZS 3500.4
and the NZBC also have particular requirements when a safe tray must be
installed.
The water heater must be maintained in accordance with the Owner's Guide and
Installation Instructions. Refer to "Maintenance Requirements" on page 14 and
to "Anode Inspection and Replacement" on page 17.
If this water heater is to be used where an uninterrupted hot water supply is
necessary for your application or business you should ensure that you have
back-up redundancy within the hot water system design. This should ensure the
continuity of hot water supply in the event that this water heater were to become
inoperable for any reason. We recommend you seek advice from your plumber
or specifier about your needs and building back-up redundancy into your hot
water supply system.
TO TURN OFF THE WATER HEATER
If you plan to be away from home for only a few nights, we suggest you leave
the water heater switched on.
If it is necessary to turn off the water heater:

Switch off the electrical supply at the isolating switch(s) to the water heater,
at the switchboard and adjacent to the water heater (if installed).

Close the cold water isolation valve at the inlet to the water heater.
TO TURN ON THE WATER HEATER

Open the cold water isolation valve fully on the cold water line to the water
heater.

Switch on the electrical supply at the isolating switch(s) to the water heater,
at the switchboard and adjacent to the water heater (if installed).
GOING ON HOLIDAY?
If you plan to be away from home for one or two nights, we suggest you leave
the water heater switched on. However, if you plan to stay away more than a few
nights, conserve energy by switching the water heater off at either the
switchboard or isolating switch (if one is installed).
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