Rinnai Tankless RUCS/RUS water quality limits
Rinnai Tankless RUCS/RUS water quality limits: reference table for the tankless water heater (Non-SENSEI series): a quick-reference table with notes.
Rinnai Tankless RUCS/RUS water quality limits table
| Contaminant | Maximum level |
|---|---|
| Total hardness | Up to 200 mg / L |
| Aluminum | Up to 0.2 mg / L |
| Chlorides | Up to 250 mg / L |
| Copper | Up to 1.0 mg / L |
| Dissolved CO2 | Up to 15.0 mg / L or PPM |
| Iron | Up to 0.3 mg / L |
| Manganese | Up to 0.05 mg / L |
| pH | 6.5 to 8.5 |
| TDS | Up to 500 mg / L |
| Zinc | Up to 5 mg / L |
How to use the Rinnai Tankless RUCS/RUS water quality limits table
Find your exact model in the first column and read across the row. Values in the Rinnai Tankless RUCS/RUS water quality limits table are a summary for quick reference; the rating plate on the unit and the manufacturer's manual for your model always decide. If your model is not listed, or a value looks different from what you see on the unit, check the manual before changing anything.
Notes
- Scale build-up shows as code LC# on a controller (LC on the status monitor without one); flush the heat exchanger.
- ScaleCutter parts: 103000038 (system), 103000039 (refill).
Applies to: RUCS65i, RUCS75i (indoor); RUS65e, RUS75e (outdoor)
Rinnai models this applies to
C199eC199iR50LSiR63LSe2R75LSeR75LSiR94LSeR94LSiR98LSeR98LSe-ASMER98LSiR98LSi-ASMERC80eRC80iRC98eRC98iRE140eRE140iRE160eRE160iRE180eRE180iRE199eRE199iREP160eREP160iREP199eREP199iRL75eRL75e(A)RL75iRL75i(A)RL94eRL94iRLX94iRU80eRU80iRU90eRU98eRU98iRUC80iRUC90iRUC98iRUCS65iRUCS75iRUR98eRUR98iRUS65eRUS75eV53DeV53eV65eV65iV75eV75iV94eV94iV94Xi
Rinnai Tankless Water Heater error codes →
Source: Rinnai KCM Series (RUCS/RUS) Installation and Operation Manual (U328-0700X04(00)), Water Quality, p.6. 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.