Rheem MPi 551 Series Owner's Manual And Installation Instructions page 42

COMMISSIONING
TO TURN OFF THE WATER HEATER
If it is necessary to turn off the water heater on completion of the installation, such as on a building site or
where the premises are vacant, then:
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.
Notes
The freeze protection system will be rendered inoperable if electrical power is not available at the water
heater.
Damage caused by freezing due to the unavailability of power at the water heater is not covered by the
Rheem warranty (refer to
If the power has been switched off to the water heater and there is a risk of freezing, then it is necessary
to drain the water heater (refer to
DIAGNOSTIC FEATURES OF THE HEAT PUMP CONTROLLER
An operating mode monitor is located on the front of the heat pump module and houses a green and a red
LED. The green LED, marked "NORMAL", indicates the current operating mode of the heat pump water
heater and the red LED, marked "ATTENTION", indicates a fault mode.
The green LED will emit either a constant glow or a series of flashes, with a 2 second interval between each
series. A series of long green flashes may also be emitted.
The red LED will emit either a solid glow or a series
of flashes, with a 2 second interval between each
series. A series of flashes indicates there may be a
particular fault condition with the system.
The modes are:
Green LED Red LED
solid green off
(remains on)
1 x green off
2 x green off
3 x green off
4 x green off
long green off
rapid green off
no green off
(remains off)
Green LED Red LED
off 1 x red
off 3 x red
off 4 x red
off 5 x red
off 6 x red
off 7 x red
off 8 x red
off 9 x red
solid green solid red
(remains on) (remains on)
"Terms of the Rheem Warranty"
"Draining The Water Heater"
Operational Modes
Standby mode – water is hot
Call for heating received – system checks performed
Note: unit may wait and continue flashing until compressor has cooled from its
last operation
Heat pump preheating
Heat pump operation – compressor and fan running
Freeze protection operation – circulator on
Heating unit on –
ambient air temperature below 3°C to 5°C or above 45°C to 55°C
System start up – heating unit on
No power at the water heater or to the heat pump or a possible fault condition
Refer to notes overleaf before calling for service
Indicator or Fault Modes
Compressor over temperature (possible circulator fault)
Compressor cooling fault condition
Tank thermistor fault condition
Evaporator thermistor fault condition
Compressor thermistor fault condition
Heat exchanger water outlet sensor fault condition
Water flow fault
Refrigeration system (compressor) fault condition
Call for service
System reset – release button
42
on page 47).
on page 44).
Heating unit on
Heating unit on
Heating unit on
Heating unit on
Heating unit on
Heating unit on
Heating unit on
Heating unit off
Heating unit off