Rinnai RUS75e series User Manual

58 KCM Series Manual
  
 Electrical Grounding
licensed
professional
only
Check all components for electrical short.
 Condensate Trap is full
Check condensate trap and drain line for blockage.
licensed
professional
only
Replace condensate trap.

Outgoing Water
Temperature Sensor
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Replace sensor.

Heat Exchanger Outgoing
Temperature Sensor

Exhaust Gas Temperature
Sensor

Outside Temperature
Sensor

Modulang Solenoid Valve
Signal
Check modulang gas solenoid valve wiring harness for loose or damaged terminals.
Measure resistance of valve coil.

High Exhaust Gas
Temperature
Check heat exchanger surface for hot spots which indicate blockage due to scale
build-up. Refer to heat exchanger ushing instrucons within this manual. Hard water
must be treated to prevent scale build up or damage to the heat exchanger.
Contact a licensed professional.
 Combuson Fan
Ensure fan will turn freely.
Check wiring harness to motor for damaged and/or loose connecons.
Measure resistance of motor winding.
 Water Flow Control
The water ow control valve has failed to close during the bath ll funcon. Immediately turn
o the water and disconnue the bath ll funcon. Contact a licensed professional to service
the appliance.
 PC Board
Check PC board DIP switches for correct posion.
Check the connecon harness at the connecon on the PC board.
Replace PC board.
 Solenoid Valve Circuit Replace the PC Board.
 Flame Sensing Device Replace the PC Board.




Scale Build-up in Heat
Exchanger (when checking
maintenance code history,
“00” is substuted for
“LC”)
LC (only when a controller is installed , the monitor shows LC0~LC9) indicates that there is scale
build up in the heat exchanger and that the heat exchanger needs to be ushed to prevent
damage. Refer to the ushing instrucons in the manual. 

To operate the water heater temporarily unl the heat exchanger can be ushed, push the On/
O buon (when a controller is installed) on the temperature controller 5 mes. Repeated LC
codes will eventually lockout the water heater.
Please call Rinnai technical department.

Maintenance has been
performed
(with controller only)
Indicates a licensed professional performed maintenance or corrected an issue.


Nothing happens when
water ow is acvated.
Clean inlet water supply lter.
On new installaons ensure hot and cold water lines are not reversed.
Verify you have at least the minimum ow rate required to re unit.
licensed
professional
only
Check for cold to hot cross over. Isolate circulang system if present. Turn o cold water to the
unit, open pressure relief valve; if water connues to ow, there is bleed over in your plumbing.
Verify turbine spins freely.
Measure the resistance of the water ow control sensor.
If the display is blank and clicking is coming from the unit, disconnect the water ow servo
motor (GY, BR, O, W, P, BL, R). If the display comes on replace the water ow servo motor.

Rinnai RUS75e series Specifications

General

Brand	Rinnai
Model	RUS75e series
Category	Water Heater
Language	English