HVACopediaRheem · Heat pump
4 flashes (L terminal) L-terminal fault output: Locked rotor
What the control is telling you
Equivalent to code L4. Shown on an L-terminal compatible conventional thermostat when the unit is wired 24VAC (non-communicating).
Applies to: (-)PRL-JEC 2-stage 16 SEER heat pumps: RPRL/UPRL-024JEC, -036JEC, -048JEC, -060JEC
Likely causes
- Bad run capacitor
- Low line voltage
- Seized compressor
Test and repair steps
- Read the ICC display.
- Follow code L4 checks.
Settings for these units
Outdoor unit clearances · Rheem/Ruud PRL-JEC heat pump (Comfort Control2 ICC)
| Location | Minimum |
|---|---|
| Above unit (fan discharge) | 60 in. [1524 mm] |
| Coil air inlets (3 sides) | 6 in. [152 mm] |
| Service access side | 24 in. [610 mm] |
| Between two units (grille sides aligned) | 12 in. total (6 in. per unit) |
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
- 02 High side fault (compressor limit opened 4 times)
- 2 flashes (L terminal) L-terminal fault output: High pressure control trip
- 03 Short cycling
- 3 flashes (L terminal) L-terminal fault output: Unit short cycling
- 05 Open circuit - compressor will not run
- 5 flashes (L terminal) L-terminal fault output: Compressor will not run, open circuit
- 06 Compressor open start circuit
- 6 flashes (L terminal) L-terminal fault output: Open start circuit
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Source: Rheem (-)PRL-JEC Heat Pump Installation Instructions, 12.7 Conventional 24VAC Thermostat Control Wiring (L terminal output), p.31. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.