Installation Guide

88 Rinnai Tankless Water Heater Installation and Operation Manual
Scale build-up will affect the performance of the water heater. Water should be treated. Rinnai offers
Southeastern Filtration’s “ScaleCutter Water Conditioning System” that provides superior lime scale
prevention and corrosion control by feeding a blend of scale control compounds into the cold water supply.
NOTE
12. Operate the pump and allow the vinegar to circulate through the water heater for at least 1 hour
at a rate of four gallons per minute (15.1 liters per minute).
13. Display shows “60” (Figure 97) which indicates the remaining flush time in minutes. The number
decreases by 1 every minute. For some reasons, flushing needs to be paused, stop the pump.
The number on the display does not decrease while the unit does not detect water flow. When
the pump resumes operation, the remaining flush time resumes decreasing as well.
15. Turn off the pump.
16. Rinse the vinegar from the water heater as follows:
A. Remove the free end of the drain hose (H3) from the pail. Place in sink or outside to drain.
B. Close service valve (V2) and open shutoff valve (V4). Do not open shutoff valve (V3).
C. Allow water to flow through the water heater for five minutes.
D. Close shutoff valve (V4). When unit has finished draining remove the in-line filter at the cold
water inlet and clean out any residue. Place filter back into unit and open valve (V4).
E. Close service valve (V1) and open shutoff valve (V3).
17. Push the power button, and the display shows “End” (Figure 99).
14. After 60 minutes flushing time completes, display shows “rnS” (rinsing) (Figure 98) and beeping
sound is observed.
18. Disconnect all hoses.
19. Install the front panel, restore gas supply to the water heater, and push the power button twice
on the controller to put the unit back to normal mode.
Figure 98
Figure 97
Figure 99
End
rnS
60