Rinnai E110CN Installation & Servicing Instructions Manual page 65

CP
H2
Flushing
Flushing and draining
Cleaning the Brazed Plate Heat exchanger (Every 2 year maintenance)
The brazed plate heat exchanger should be cleaned at the service interval every 2
years. Failure to flush the brazed plate heat exchanger will cause damage to it. Follow
the procedure below for cleaning the brazed plate heat exchanger.
1. Turn off the DHW function on 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 hot water line at service valve (V1).
4. Connect drain hose (H3) to service valve (V2).
5. Pour approximately 4 gallons of virgin, food grade, white vinegar or citric acid into
pail.
6. Place the drain hose (H3) and the hose (H2) to the pump (CP) 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 (CP) and allow the cleaning solution to circulate through the
brazed plate heat exchanger for at least 45 minutes.
9. Turn off the pump (CP).
10. Rinse the cleaning solution from the brazed plate heat exchanger as follows:
a. Remove the free end of the drain hose (H3) from the pail
b. Close service valve, (V2), and open shutoff valve, (V4). Do not open shutoff
valve, (V3).
c. Disconnect both H1 and H3 from the service valves
d. Connect H3 to V1 and place the end of the hose in a drain
e. Allow water to flow through the brazed plate heat exchanger for 5 minutes
f. Close service valve, (V1), and open shutoff valve, (V3).
11. Disconnect all hoses.
V1 V2
H1
V3 V4
H3
Drain
Draining
V1 V2
V3 V4
H1
figure 37
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