36
UGT Series Manual
Code Definition
Remedy
19
Electrical Grounding
licensed
professional
only
Check all components for electrical short.
32
Outgoing Water
Temperature Sensor
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Replace sensor.
33
Heat Exchanger Outgoing
Temperature Sensor
34
Combustion Air
Temperature Sensor
Check for restrictions in air flow around unit and vent terminal.
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
Ensure fan blade is tight on motor shaft and is in good condition.
Replace sensor.
51
Inlet water temperature
thermistor (UGT-199 only)
Check sensor wiring for damage.
Measure resistance of sensor.
Clean sensor of scale build-up.
52
Modulating Solenoid Valve
Signal
Check modulating gas solenoid valve wiring harness for loose or damaged terminals.
Measure resistance of valve coil.
61
Combustion Fan
Ensure fan will turn freely.
Check wiring harness to motor for damaged and/or loose connections.
Measure resistance of motor winding.
65
Water Flow Control
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.
70
PC Board
Check PC board DIP switches for correct position.
Check the connection harness at the connection on the PC board.
Replace PC board.
71
Solenoid Valve Circuit
Replace the PC Board.
72
Flame Sensing Device
Verify flame rod is touching flame when unit fires.
Check all wiring to flame rod.
Remove flame rod and check for carbon build-up; clean with sand paper.
Check inside burner chamber for any foreign material blocking flame at flame rod.
Measure micro amp output of sensor circuit with flame present.
Replace flame rod.
79
Water Leak Detected
Water has been detected at the bottom of the unit. Turn off water supply. Check all plumbing
internally for leakage.
LC #
(LC0,
LC1,
LC2,…)
Scale Build-up in Heat
Exchanger (when 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 on the temperature controller 5 times. Repeated LC codes will eventually lockout
the water heater.
Please call technical department at 1-800-363-9354.
FF
Maintenance has been
performed
Indicates a licensed professional performed maintenance or corrected an issue.
No
code
Nothing happens when
water flow is activated.
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.
licensed
professional
only
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.
