Rinnai RUR98i - Flushing the Heat Exchanger

70 KBP Series Manual
Water Heater
Pressure Relief Valve
3/4" Ball Valve
3/4" Union
Check Valve
S
Pressure Regulator
Circulating Pump
Solenoid Valve
Boiler Drain Valve
KEY
G a s
S u p
p l y
V1
V3
V2
V4
H1
H2
H3
Circulating Pump
C o l d
W
a t e r
L i n e
H o t
W
a t e r
L i n
e
n
- l i n e
F i l t e r
I
Rinnai
An LC0~LC9 or “00” or 58 diagnosc code indicates the unit is beginning to lime up and must be ushed. Failure
to ush the appliance will cause damage to the heat exchanger. Damage caused by lime build-up is not covered
by the unit’s warranty. Rinnai strongly recommends installaon of isolaon valves to allow for ushing of the
heat exchanger.
1. Disconnect electrical power to the water heater.
2. Close the shuto 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 service valve (V1).
5. Pour 4 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 soluon.
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 water heater for at least 1 hour at a rate
of 4 gallons per minute (15.1 liters per minute).
9. Turn o the pump.
10. 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 shuto valve,
(V4). Do not open shuto valve, (V3).
c. Allow water to ow through the water heater for
10 minutes.
d. Close shuto valve (V4). When unit has nished
draining remove the in-line lters at the cold
water inlet and the hot water outlet and clean out
any residue. Place lter back into unit and open
valve (V4).
e. Close service valve, (V1), and open shuto valve,
(V3).

11. Disconnect all hose
12. Restore electrical power to the
water heater.
Following ush procedure call
technical assistance (1-800-621-
9419) for PCB reset informaon.