Rinnai Water Treatment Priority Order
For Rinnai owners, water treatment priority order: (1) Address hardness first if water is above 12 GPG -- scale on the copper heat exchanger causes failure within 3--8 years in very hard water (above 15 GPG) without treatment. (2) Address chloramine second if the utility uses chloramine disinfection -- check your annual water quality report (available at your utility's website) for "chloramine" or "combined chlorine" in the disinfection section. (3) Consider an annual Rinnai descaling even with full water treatment -- citric acid flush protects against residual scale nucleation. (4) Confirm the softener bypass is set correctly during Rinnai service calls -- the softener should never be left in bypass for extended periods if the Rinnai is in daily use.