Rinnai RX water treatment and flushing by hardness
Rinnai RX water treatment and flushing by hardness: reference table for the tankless water heater (SENSEI RX/CX series): a quick-reference table with notes.
Rinnai RX water treatment and flushing by hardness table
| Class | Hardness mg/L | Grains/gal | Treatment | Flushing |
|---|---|---|---|---|
| Soft | 0-60 | 0-4 | None | None |
| Slightly hard | 61-120 | 4-7 | Softener or Rinnai Scale Cutter recommended | Residential once/year; commercial twice/year |
| Moderately hard | 121-160 | 7-9 | Softener or Rinnai Scale Cutter recommended | Residential once/year; commercial twice/year |
| Very hard | 161-200 | 9-12 | Softener or Rinnai Scale Cutter strongly recommended | Residential once/year; commercial twice/year |
| Extremely hard | 200+ | 12+ | Softener or Rinnai Scale Cutter required | Residential once/year; commercial twice/year |
How to use the Rinnai RX water treatment and flushing by hardness table
Find your exact model in the first column and read across the row. Values in the Rinnai RX water treatment and flushing by hardness 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
- Use parameter 03 (Service Soon) to remind the owner to flush.
Applies to: RX199i, RX180i, RX160i, RX130i, RXP199i, RXP160i (indoor)
Rinnai models this applies to
RX130iRX160iRX180iRX199iRXP160iRXP199i
Rinnai Tankless Water Heater error codes →
Source: Rinnai SENSEI RX Residential Installation and Operation Manual (100000839(03)), Table 3 Recommended Water Treatment, p.11. 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.