Rheem Maximus Manual page 43

Alarm ('A')
and Alert
('T') Codes
Energy Cutout (ECO) switch is open. This will disable
A016
the heater.
Flue (exhaust) gas temperature has exceeded 155°F.
A017
This will disable the heater.
Flue temperature sensor (thermistor) detected open.
A018
This will disable the heater.
Flue temperature sensor (thermistor) detected short
A019
circuited. This will disable the heater.
Lower tank (inlet) temperature sensor (thermistor)
T020
detected open.
Lower tank (inlet) temperature sensor (thermistor)
T021
detected short circuited.
Upper tank temperature sensor detected open. This
A022
will disable the heater.
Upper tank temperature has exceeded 205°F. This will
A023
disable the heater.
Upper tank temperature sensor detected short
A024
circuited. This will disable the heater.
BEFORE YOU CALL FOR SERVICE...
Description Current Alarm Screen Display
A016 High Tank Temperature. Call Tech Service.
->Clear error code by pressing clear button. Refer
to use and care manual for troubleshooting, or contact
technical support.
A017 High Flue Temp. Recycle unit ON/OFF.
->Blower will continue to run until exhaust
temperature has decreased. If problem persists contact
technical support.
A018 Flue Temp Sensor open. Check wiring.
->Check wiring to sensor. If condition persists refer
to use and care manual or contact technical support.
A019 Flue Temp Sensor shorted. Call Tech Svc.
->Check wiring to sensor. If condition persists refer
to use and care manual or contact technical support.
T020 Lower Tank Sensor open. Check wiring.
->Check wiring to sensor. If condition persists refer
to use and care manual or contact technical support.
T021 Lower Tank Sensor shorted. Call Tech Svc.
->Check wiring to sensor. If condition persists refer
to use and care manual or contact technical support.
A022 Upper Tank Sensor open. Check wiring.
->Check wiring to sensor. If condition persists refer
to use and care manual or contact technical support.
A023 Upper Tank temp. too hot. Call Tech Svc.
->Clear error code by pressing clear button. Refer
to use and care manual for troubleshooting, or contact
technical support.
A024 Upper Tank sensor shorted. Call Tech Svc.
->Check wiring to sensor. If condition persists refer
to use and care manual or contact technical support.
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