Troubleshooting; Diagnostic Codes - A.O. Smith ProLine XE Installation Instructions And Use & Care Manual

DIAGNOSTIC CODES

WARNING! Electric Shock Hazard; Disconnect power before servicing. Do not remove the plactic guard from over wiring. Do not
touch electrical wiring. Failure to do so can result in death or electrical shock.
DISPLAY SHOWS
- -- --- (series of dashes)
ICE
HPO
*
EUC
ELC
SF
*
ECF
*
E20 or E21
E30 or E31
E50 or E51
E10 or E11
E40 or E41
*
E60
*
Edr
EPL
*
EDH
NOTE: The diagnostic codes listed above are the most common. If a diagnostic code not listed above is displayed, contact Residential
Technical Support referencing the number on the front of this manual.
*
There may be an audible alarm associated with this error. To cancel the audible alarm, press any button on the UIM.
20 • Residential Hybrid Electric Heat Pump Water Heater Use and Care Guide
INDICATES
Unit is doing a system
diagnostic.
Heat pump is in defrosting
cycle.
Ambient temperature <45°F
or >120°F, average tank
temperature of 59°F or less.
Upper element is not
functioning
Lower element is not
functioning
The air filter is dirty.
The heat pump compressor is
starting/stopping frequently.
Upper Temperature Sensor is
not functioning.
Lower Temperature Sensor is not
functioning.
Heat Pump Suction Temperature
Sensor is not functioning.
Heat Pump Coil Temperature
Sensor is not functioning.
Heat Pump Discharge
Temperature Sensor is not
functioning.
Upper and Lower Temperature
Sensor are not functioning
Not enough water in the tank
(tank not full).
Power supply voltage is too low.
Compressor Discharge
Temperature is too high.
CORRECTIVE ACTION
Normal operation--no action
Refer to Page 22, Step 2 "Check Upper Heating Element." and
Page 27 "Replacing the Heating Element"
Refer to Page 22, Step 2 "Check Upper Heating Element." and
Page 27 "Replacing the Heating Element"
Refer to "Air Filter Maintenance" page 30.
1. If compressor is running and fan is not operating, call
residential technical support.
2. Clean the air filter. See "Air Filter Maintenance" section
on page 30.
3. Check installation location against recommended
confined space requirements (step 2, page 9).
Power off (Power Cycling the unit, page 25), disconnect and
reconnect J2 and J5 connections from control board, inspect
wire for damage, re-install UIM, reconnect power. If error
persists, replace temperature sensor.
Open all hot water taps in home and run until water
(uninterrupted) flows from all open hot water taps.
Check for loose electrical connections, refer to "Power
Cycling the Unit", page 25
Call Residential Technical Support