Rheem RTGH-RH11DV Use And Care Manual page 70

Error Code Error Code Description
Er:67
Flame Signal Detected
Er:72
Er:73 DIP Switch is abnormal
Er:76 Poor Communication
Cascade Communication
Er:78
Exhaust NTC detects Vent
Temperature is Greater than
Er:94
(185°F / 85°C when High
Temp set point is Selected)
Table 29 –Diagnostics and Suggested Corrective Actions
Press the Power button to clear the Error Code.
If Error happens again:
1. Turn power OFF and ON at the main power switch internal to the water heater.
2. Ensure fan inlet hole is completely open after turning the power OFF and ON.
AGM Error
3. Check wiring connections to the AGM. Ensure all are secure.
4. Check AGM operation.
5. Replace AGM components.
6. If the problem persists, replace the main control.
This Error Code will go away when the condition is remedied.
If Error happens again:
1. Check the water heater cover. Ensure it is secure. Flame detection sensor can detect an
external light source.
before Ignition
2. Check flame detection sensor. Ensure connections are secure. Normal operating settings
are more than 2.5DC before ignition, less than 2.5DC after ignition.
3. If the problem persists, replace the main control.
This Error Code will go away when the condition is remedied.
If Error happens again:
1. Check dip switches. Ensure switches match the ratings plate requirements of the water heater. See
dip switch details, this manual, for default settings.
2. If the problem persists, replace the main control.
This Error Code will go away when the condition is remedied.
If Error happens again:
1. Check connections from main control to display panel.
2. If the problem persists, replace the display and/or the main control.
NOTE: This error will only appear in a cascaded system.
1. Turn power OFF and ON at the appliance display panel.
2. If error reappears, ensure all cascaded appliances are powered ON.
3. If error reappears, check Installer Mode parameter 10:Cn at among the both units.
Ensure the setting as "on" in 10:Cn of Installer Mode.
Error
4. If error reappears, check the wire cables into the 'Main PCB' connector inside both units.
Ensure the connection of cascade cable between both appliances.
5. If there was no problem wiring connection, replace damaged cables.
6. If the problem persists, replace the main control.
This Error Code will go away when the condition is remedied.
If Error happens again:
1. Check if dip switch High Fire setting is ON. Switches 6 and 7 should be OFF for normal operation.
2. Check exhaust temperature sensor. Ensure connections are secure.
149°F/ 65°C
3. Check sensor resistance. If resistance is zero, replace the sensor.
4. Check exhaust vent for blockage.
5. If the problem persists, replace the control.
6. If the problem persists, replace the heat exchanger.
Possible Remedies
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AP18733 REV. 3.2.17