L4 Locked rotor lockout

What the control is telling you

Compressor ran less than 15 seconds on four (4) consecutive starts during the same call; the ICC locks out the compressor (display flashes L then 04/4). Manual reset required. Reported as 4 flashes on the L terminal.

Applies to: (-)PRL-JEC 2-stage 16 SEER heat pumps: RPRL/UPRL-024JEC, -036JEC, -048JEC, -060JEC

Likely causes

• Bad run capacitor
• Low line voltage
• Excess refrigerant in compressor (flooding/migration)
• Seized compressor bearings

Test and repair steps

1. Test the run capacitor and replace if out of spec.
2. Measure line voltage at the compressor while starting; it must be within ±10% of nameplate (197-253V for 208/230V units).
3. Make sure the crankcase heater works; at startup or after a long shutdown it should be powered 12 hours before starting the compressor.
4. Check charge for overcharge/flooding.
5. Check compressor windings for correct ohms and ground.
6. Hard-start components are factory installed - verify they are intact.
7. Reset the ICC after the cause is fixed press TEST for 1 second with an insulated probe (preferred), or cycle 24VAC (pull R or C) or cycle line power.

Settings for these units

Outdoor unit clearances · Rheem/Ruud PRL-JEC heat pump (Comfort Control2 ICC)

Do not reduce the 60 in. discharge or 24 in. service clearances.

Inlet clearances under 6 in. reduce capacity and efficiency.

Models that show this code

4 models in Rheem/Ruud PRL-JEC heat pump (Comfort Control2 ICC)

Other codes on the same units

• d1 No shared data
• d3 Airflow CFM mismatch
• d4 Memory card invalid for device
• d8 Old shared data
• L6 Open start circuit lockout
• L7 Open run circuit lockout
• L21 Low pressure control lockout
• L29 High pressure control lockout