Rheem MPi 551 Series Owner's Manual And Installation Instructions page 8

ABOUT YOUR WATER HEATER
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 to the water heater.
Close the cold water isolation valve at the inlet to the water heater.
Note: If there is a risk of freezing conditions, the electrical supply to the water heater should not be switched
off, otherwise damage could result (refer to
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 to the water heater.
Check and if required reset the timer, if one is installed.
When power is turned on or reconnected to the water heater, the green LED will flash rapidly for three (3)
seconds. The LED display will then return to the current operational status.
The water heater may take up to forty five minutes to commence operating when the power supply is
switched on. The heat pump will only operate when power is available at the water heater, the water in the
storage tank requires heating, the heat pump compressor is cool and the ambient air temperature is within
the heat pump‟s operating temperature range of between a minimum of 3°C to 5°C and a maximum of 45°C
to 55°C. If the ambient temperature is outside of this range, the water heater will commence heating with the
booster heating unit.
When the heat pump is operating, the system will switch to the booster heating unit if the detected ambient
air temperature is outside the operating temperature range of between a minimum of 3°C to 5°C and a
maximum of 45°C to 55°C.
The system will not switch back to heat pump operation from the booster heating unit if the detected ambient
air temperature has moved back within the heat pump‟s operating temperature range. The heating cycle will
be completed by the booster heating unit.
Note: The heat pump may not turn on immediately after either having just completed a heating cycle and
more hot water is drawn from the water heater or power is shut down to the compressor, either during or at
the end of a heating cycle. The heat pump will wait until the compressor has cooled down and the conditions
for start up are favourable in order to protect the compressor from damage. This will be a minimum of forty
five (45) minutes and may take up to ninety (90) minutes from the last heating cycle.
GOING ON HOLIDAYS
If you plan to be away from home for a few nights, we suggest you leave the water heater switched on. If you
plan to be away for a longer period, conserve energy by switching off the isolating switch to the water heater.
It is not advised to switch off the water heater if there is the risk of freeze conditions. Refer to
The Water Heater"
on page 8.
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 water heater must be maintained in accordance with the Owner‟s Guide and Installation Instructions.
"Regular Care"
Refer to on page 10 and to
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.
"Freeze Protection"
on page 5).
"Anode Inspection and Replacement"
8
"To Turn Off
on page 12.