Rinnai Demand Duo R-Series Installation And Operation Manual page 49

Recirculation Low Flow
6 3
• Ensure the inlet water filter is clean and
free of debris.
• Ensure Parameter setting are correctly
set for recirculation mode.
• Ensure Pump supply voltage.
• Ensure the wiring harness to the pump
and PCB for damaged and/or loose
connections.
• Ensure air is removed from the
recirculation line.
Water Flow Control
6 5
The water flow control valve has failed to
close during the bath fill function.
Immediately turn off the water and
discontinue the bath fill function. Contact a
licensed professional to service the
appliance.
Bypass Flow Servo
6 6
• Measure the resistance values and
voltage of the bypass servo valve.*
• Ensure the harness and connector are
not wet.
• If the voltage from the PC Board is
abnormal, replace the PC Board;
otherwise, replace the bypass servo
valve.
PC Board
7 0
• Check the connection harness at the
connection on the PC board. Inspect for
any damage.
• Replace PC board.
Solenoid Valve Circuit
7 1
Replace the PC Board.
Flame Sensing Device
7 2
Replace the PC Board.
Water Leak Detected
7 9
Water has been detected at the bottom of
the unit. Turn off water supply. Check all
plumbing internally for leakage.
Demand Duo™ R-Series (REC) Installation and Operation Manual
Scale Build-up in Heat Exchanger (when
L c
checking maintenance code history,
#
"00" is substituted for "LC")
• LC0~LC9 indicates that there is scale
build up in the heat exchanger and that
the heat exchanger needs to be flushed
to prevent damage. Refer to the flushing
instructions in the manual. Hard water
must be treated to prevent scale build
up or damage to the heat exchanger.
To operate the water heater temporarily
until the heat exchanger can be flushed,
push the "On/Off" button five times.
Repeated LC codes will eventually lockout
the water heater.
Service Soon
S S
• Clean inlet water supply filter.
• On new installations ensure hot and cold
water lines are not reversed.
• Verify you have at least the minimum
flow rate required to fire unit.
• Check for cold to hot cross over. Isolate
circulating system if present.
• Turn off cold water to the unit, open
pressure relief valve; if water continues
to flow, there is bleed over in your
plumbing.
• Verify turbine spins freely.
• Measure the resistance of the water flow
control sensor.
• If the display is blank and clicking is
coming from the unit, disconnect the
water flow servo motor (GY, BR, O, W,
P, BL, R). If the display comes on then
replace the water flow servo motor.
Maintenance has been performed
f f
Indicates a licensed professional performed
maintenance or corrected an issue.
No Code - Nothing happens when pump is
activated
• Clean inlet water supply filter.
• Verify you have at least the minimum flow
rate required to fire unit.
• Verify turbine spins freely.
• Measure the resistance of the water flow
control sensor.
49