Flush The Dhw Heat Exchanger - Rinnai I Series Installation And Operation Manual

This boiler includes a service indicator/reminder (also called an LC diagnostic code). When selected
in the parameter settings, an LC code will display on the controller indicating that it is time to flush
and service the boiler. Failure to flush the boiler will cause damage to the plate heat exchanger.
Damage caused by lime build-up is not covered by the boiler's warranty. Rinnai strongly
recommends installation of isolation valves to allow for flushing of the plate heat exchanger.
1. Disconnect electrical power to the boiler.
2. Close the shutoff valves on both the hot
water and cold water lines (V3 and V4).
3. Connect pump outlet hose (H1) to the cold
water line at service valve (V2).
4. Connect drain hose (H3) to the hot water
line at service valve (V1).
5. Pour four gallons of undiluted virgin, food
grade, white vinegar into pail.
6. Place the drain hose (H3) and the hose
(H2) to the pump inlet into the cleaning
solution.
7. Open both service valves (V1 and V2) on
the hot water and cold water lines.
8. Operate the pump and allow the vinegar
to circulate through the boiler for at least
1 hour at a rate of four gallons per minute
(15.1 liters per minute).
9. Turn off the pump.
10. Rinse the vinegar from the boiler 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 boiler
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).
11. Disconnect all hoses.
12. Restore electrical power to the boiler.
Rinnai I-Series Condensing Boiler Combi Manual
IMPORTANT
Scale build-up will affect the
performance of the boiler. Water should
be treated. Rinnai offers Southeastern
Filtration's "ScaleCutter Water
Conditioning System" that offers superior
lime scale prevention and corrosion
control by feeding a blend of control
compounds into the cold water supply.
H3
H2
V1 V2
V4
V3
H1
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