Error A112 Shutoff Valve Not Open; Error A121 No Water Detected In Tank; Error T009 N Ogas Detected; Error T020-T021 Lower Tank Sensor Open /Shorted - Rheem TRITON Service And Training Manual

Troubleshooting Error Codes

Error A112 Shutoff Valve Not Open

•
Confirm the Molex connectors from valve to water heater wiring is securely connected.
•
Confirm no wires are loose/damaged in Molex connectors from valve to water heater.
•
Manually open the shutoff valve (see page 59), clear the alarm. If the alarm persists, replace the automatic shutoff
valve.

Error A121 No Water Detected in Tank

• Ensure tank is full and all air has been purged
• If tank is full, check the current alarms to see if any other alert/alarm is present for an OPEN ANODE such as T123,
T128, or T133 (Certain software versions display these as A codes instead of T codes)
• Follow diagnostic and troubleshooting steps for that code.
Error T009 No Gas Detected
The gas pressure switch is open. You can clear this error code by pressing the clear button on the current alarm screen.
Check the following to see if the problem can be resolved.
• Check wiring to the switch for broken/damaged wires.
• Check inlet gas pressure at unit. If gas pressure ever drops below 3.5"wc the T009 alert will occur.
• If minimum gas pressure is present and wires are intact, replace the gas pressure switch.
Error T020 Lower Tank Sensor Open
Control senses the lower tank temperature sensor open. This will not disable the unit or keep it from heating water.
The alert will clear on its own when the issue is resolved.
• Confirm wiring harness is securely connected to lower tank temperature sensor and confirm the wiring harness at the P2
connection on the control board is secure.
• If no wiring is loose, disconnect wiring from lower temperature probe. Check ohms reading across the pins of the
sensor. A good sensor should read between 1K to 36K ohms. If sensor reads open, replace the sensor.
• If sensor has a reading between 1K to 36K ohms, reconnecting the wiring to the sensor. Turn off power and disconnect
P2 harness from ignition control board and check the ohms reading across the 2 blue wires. Your reading should be
about the same as the reading you got on the sensor. If not, replace the wiring harness. If readings match and error
won't clear then replace the ignition control board
Error T021 Lower Tank Sensor Shorted
The control board is detecting a short in the lower temperature probe wiring. This will not disable the unit or keep it
from heating water.
• Disconnect the wiring from lower temperature probe. If unit gives an alarm for T020, replace the lower
temperature probe.
• If you do not get the T020, turn the unit off. Disconnect the lower temperature probe wiring and the P2 harness at
the ignition control board and check for continuity across the wires at the lower temperature probe. If you have
continuity, there is a short in the wiring harness. Replace the wiring harness.
• If above checks determined no resolution, replace the ignition control board.
Triton Service Manual SVC1020T ; Rev 4
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80 and 100 gallon chassis