Rinnai Error Code Diag history: Maintenance code history viewer (last 9 codes) (Tankless)
Rinnai error code Diag history on a tankless water heater means: Maintenance code history viewer (last 9 codes). It is also called Rinnai diagnostic code Diag history.
Homeowner? What Rinnai code Diag history means for you
Usually minor Your tankless water heater is reporting: Maintenance code history viewer (last 9 codes). This code is usually informational or minor. The safe checks below often clear it; call us if it keeps showing up.
Safe things you can check yourself
- Check that gas reaches the house: other gas appliances work, or the propane tank is not empty.
- Make sure the heater is plugged in and its breaker is on. In winter, keep the power on: it protects the unit from freezing.
- Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
- Check that the hot and cold water valves under the heater are fully open.
- If you have a remote controller, turn it off and on once. If the code comes back, call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Rinnai error code Diag history mean?
Service mode on the temperature controller that scrolls through the last nine stored maintenance codes, one after another, flashing each. Nothing is wrong when you use it; it is only a way to read past events. Controllers: MC-91-2 / MCC-91-2 on most models, MC-601 / MCC-601 on RE/REP, the RX/CX controller, and MC-601-US on KCM.
Applies to: Rinnai tankless water heaters, non-SENSEI, SENSEI, SENSEI RX/CX and KCM
Rinnai models that use code Diag history
Show all 88 models
C199eC199iCU160eCU160iCU199eCU199iCX160iCX199iCXP160iCXP199iR50LSiR63LSe2R75LSeR75LSiR94LSeR94LSiR98LSeR98LSe-ASMER98LSiR98LSi-ASMERC80eRC80iRC98eRC98iRE140eRE140iRE160eRE160iRE180eRE180iRE199eRE199iREP160eREP160iREP199eREP199iRL75eRL75e(A)RL75iRL75i(A)RL94eRL94iRLX94iRSC160eRSC160iRSC199eRSC199iRU80eRU80iRU90eRU98eRU98iRU130eRU130iRU160eRU160iRU180eRU180iRU199eRU199iRUC80iRUC90iRUC98iRUCS65iRUCS75iRUR98eRUR98iRUR160eRUR160iRUR199eRUR199iRUS65eRUS75eRX130iRX160iRX180iRX199iRXP160iRXP199iV53DeV53eV65eV65iV75eV75iV94eV94iV94Xi
Other Rinnai Tankless codes
All Rinnai Tankless Water Heater error codes →
Rinnai code Diag history: homeowner questions
What does Rinnai code Diag history mean?
Maintenance code history viewer (last 9 codes). Service mode on the temperature controller that scrolls through the last nine stored maintenance codes, one after another, flashing each. Nothing is wrong when you use it; it is only a way to read past events. Controllers: MC-91-2 /…
Is it safe to keep using my tankless water heater with code Diag history?
Usually yes. Code Diag history is normally minor, but if it keeps coming back have it checked.
Can I reset Rinnai code Diag history myself?
You can try one reset (power off for 30 seconds, then on). If Rinnai code Diag history comes back, the cause is still there and a licensed technician should check it.
Who can fix Rinnai code Diag history near me?
Aurora Star Tech Inc. repairs Rinnai tankless water heaters in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: Tankless Water Heater No Hot Water: What to Check
Troubleshooting guides
- No hot water All brands · Tankless Water Heater
- Water temperature fluctuates All brands · Tankless Water Heater
- Checking PC board fuses and thermistors Rinnai · Tankless Water Heater
- Enter installer parameter mode (A button on the PC board) Rinnai · Tankless Water Heater
- First power-up setup: gas type and indoor/outdoor (RX/CX) Rinnai · Tankless Water Heater
- Lock or unlock the controller (key symbol) Rinnai · Tankless Water Heater
- Lock or unlock the KCM controller (LOC) Rinnai · Tankless Water Heater
- Performance data readout (items 01 to 24) Rinnai · Tankless Water Heater
- Reset after cleaning the venturi or replacing the gas valve (codes 17 / 52) Rinnai · Tankless Water Heater
- Reset the Service Soon (SS) reminder Rinnai · Tankless Water Heater
- Show live flow and outlet temperature on the KCM controller Rinnai · Tankless Water Heater
- Show the last 9 stored codes (diagnostic history) Rinnai · Tankless Water Heater
- Start descaling (vinegar flush) mode on the PC board Rinnai · Tankless Water Heater
- Switch the controller between Celsius and Fahrenheit Rinnai · Tankless Water Heater
- Turn controller key beeps on or off Rinnai · Tankless Water Heater
- Weak or missing flame signal (flame rod checks) Rinnai · Tankless Water Heater
Source: Rinnai Troubleshooting TWH Diagnostic Codes (100000652), View Diagnostic Information p.72; Rinnai N-Series Residential (100000467) / with Pump (100000508) / Commercial (100000504) / RSC SENSEI (100000773) Installation and Operation Manuals, 5.6 Diagnostic Codes; Rinnai KCM Series Manual (U328-0700X04), p.56. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.