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Troubleshooting - A.O. Smith RPV series Installation Instructions And Use & Care Manual

Electric tankless water heater

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TROUBLESHOOTING

Error Codes for Point-of-Use Models
If you have a two- or four-chamber model, see page 19.
WARNING
Electric Shock Risk
Contact with the electrical parts inside the water heater can result in severe injury or death from electrical shock:
• Disconnect power by opening the circuit breaker(s) or removing the fuses before installing or servicing.
• Some models are connected to more than one branch circuit, and more than one disconnect switch may be
required to de-energize the equipment. All branch circuits must be disconnected prior to service.
The LED on the circuit board will display a series of RED fl ashes, and each series of fl ashes represents one digit in the code. A er
each sequence, the LED will fl ash GREEN. See the examples below. (Components are iden fi ed in Figure 8, page 18.)
NOTICE:
There may be mul ple codes; verify all sequences.
If you want to hear the fl ash code, press the mode bu on for two seconds. This will turn the audible beeper on. See Figure 8,
page 18.
Examples from the Table Below:
Flash Code Sequence: 12/14 (Temperature Sensor Failure). The 12/14 code would be displayed like this:
1
1 red fl ash—pause—2 red fl ashes—pause—green fl ash—one red fl ash—pause—four red fl ashes—pause—green fl ash
Flash Code Sequence: 22 (Temperature Sensor Failure). The 22 code would be displayed like this:
2
2 red fl ashes—pause—two red fl ashes—pause—green fl ash
A er you iden fy the code, locate its descrip on and solu on in the table.
Flash Code
Sequence
12/14
Temperature sensor failure
22
13/16
14/16
Temperature sensor shorted
12/13
Temperature sensor open
11
Disable switch open
17
High temperature shutdown
(This code will clear when the
condi on is corrected.)
2
/
2
Description
Turn off all power to the water heater. Open a nearby hot water fi xture
and allow water to run through the heater for about 5 minutes. Check
the resistance of all temperature sensors (thermistors), then compare the
readings. The failed sensor will be the one that has a resistance reading
(ohms) that is at least 10% to 15% diff erent from all of the others.
Check wiring. Replace as necessary.
Check wiring. Replace as necessary.
Install the missing jumper(s) on the circuit board as shown in Figure 8,
page 18. Both jumpers must be in place.
This code is triggered when the temperature of the water has exceeded
the set point by more than 8°F. 1. Turn off all power to the water heater.
Open a nearby hot water fi xture and allow water to run through the
heater for about 5 minutes. Check the resistance of the temperature
sensors (thermistors). If one of the thermistors has a resistance that
is much higher than the others, replace that thermistor. 2. If the issue
persists, the circuit board (control board) may need to be replaced.
Contact Technical Support.
1
4
Action / Solution
Electric Tankless Water Heater
17

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