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Residen al Hybrid Electric Heat Pump Water Heater Use and Care Guide
NOTE:
The diagnostic codes listed above are the most common. If a diagnostic code not listed above is displayed,
contact Residential Technical Assistance referencing the number on the front of this manual.
DIAGNOSTIC CODES
DISPLAY SHOWS
INDICATES
CORRECTIVE ACTION
“-”,”--”,”---”
Unit is doing a system
diagnostic.
Normal operation--no action
ICE
Heat pump is in defrosting
cycle.
HPO
Ambient temperature
45°F-120°F (7.2
°
C-49
°
C), average
tank temperature of 59°F (15
°
C)
or less.
EUC
Upper element is not
functioning
1. Turn off power at the circuit breaker/fuse box and
check for a loose connection at the element. For access
directions see “Replacing the Heating Element” Section
on page 29. If error persists proceed to the next step.
2. Replace non-functioning element. See “Replacing the
Heating Element” Section on page 29.
ELC
Lower element is not
functioning
1. Turn off power at the circuit breaker/fuse box and
check for a loose connection at the element. For access
directions see “Replacing the Heating Element” Section
on page 29. If error persists proceed to the next step.
2. Replace non-functioning element. See “Replacing the
Heating Element” Section on page 29.
SF
The air filter is dirty.
1. Turn off power at the circuit breaker/fuse box.
2. Clean the air filter. See “Air Filter Maintenance” Section
on page 32.
ECF
The heat pump compressor is
starting/stopping frequently.
1. Turn off power at the circuit breaker/fuse box.
2. Clean the air filter. See “Air Filter Maintenance” Section
on page 32.
3. If error persist, please contact a qualified person to
check the fan wire connection.
E20 or E21
Upper Temperature Sensor is
not functioning.
Contact a qualified person to service the unit.
E30 or E31
Lower Temperature Sensor is not
functioning.
E50 or E51
Heat Pump Suction Temperature
Sensor is not functioning.
E10 or E11
Heat Pump Coil Temperature
Sensor is not functioning.
E40 or E41
Heat Pump Discharge
Temperature Sensor is not
functioning.
Edr
Not enough water in the tank
(tank not full). This is also
referred to as “Dry Fire”.
Refer to “Verify connections and completely fill tank” Section
on page 14 Open all hot water taps in home and run until
water (uninterrupted) flows from all open hot water taps.
