In some cases air conditioning system repair can be rather complicated for an average user. However, some of the typical problems are not that serious and don’t require much more than basic skills. Even if you don’t feel like troubleshooting your Rheem air conditioner on your own, you may use the check list below to gain a better understanding of the issue and not let a service company take advantage of you.
Rheem RASL-JEC air troubleshooting
| Dual 7-Segment LEDs Display Code | Diagnostic Description | Status/Possible Cause – Troubleshooting Information |
| 0 | 0 – Standby No command for unit operation |
Normal operation |
| c | c – First Stage Cooling Unit has received a command for first stage cooling |
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| c FLASHING | c – Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active | • The unit has received a command for first stage cooling during an active anti-short cycle timer or minimum run timer. • Wait until unit timer has expired or press the TEST button to defeat short cycle delay. |
| C | C – Second Stage Cooling Unit has received a command for second stage cooling |
Normal operation |
| C FLASHING | C – Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active | • The unit has received a command for second stage cooling during an active anti-short cycle timer or minimum run timer. • Wait unit timer has expired or press the TEST button to defeat short cycle delay. |
| t | t – Test Mode | The ICC is in TEST mode |
| P | P – Protector Trip A command for compressor operation is present but no current is measured to the compressor |
• Motor protector open • Line voltage disconnected |
| 1 | 01 – Long Run Time (Compressor) The compressor has continuously run for more than 18 hours in the cooling mode. |
• Low refrigerant charge • Air ducts have substantial leakage • Dirty indoor air filter • Dirty outdoor coil |
| 2 | 02 – High Side Fault Compressor limit has opened four (4) times within a call for operation |
• Outdoor coil is dirty (cooling mode) • Outdoor fan is not running (cooling mode) • Dirty indoor coil or filter (heating mode) • Indoor blower is not running (heating mode) • Liquid line restriction • Excessive refrigerant charge |
| 3 | 03 – Short Cycling The ICC detects the run time for the past four (4) compressor cycles is less than three (3) minutes each. |
• Check thermostat wire connections (R. C. 1. & 2) • Check thermostat location in zone (too close to discharge grill) |
| L4 | L4 – Locked Rotor The ICC detects four (4) consecutive protector trips have occurred and the average run time for each trip is less than 15 seconds |
• Bad run capacitor • Low line voltage • Excessive refrigerant in compressor • Seized bearings in compressor |
| 5 | 05 – Open circuit (Compressor will not Run) • The ICC has received a command for unit operation but no current is present in the start and run circuits • The ICC will attempt to restart the unit every five (5) minutes for four (4) attempts. After that, the ICC will attempt a restart every twenty (20) minutes for up to four (4) hours. • The ICC has had a protector trip for longer than 4 hours. |
• Check for damaged, miswired. or wrong run capacitor • Check for broken wires, loose connectors, or miswired compressor • Check compressor windings for continuity • Check for open compressor internal protector |
| 6 | 06 – Compressor Open Start Circuit The ICC detects current in the Run circuit but not in the Start circuit of the compressor | |
| L6 | 06 – Compressor Open Start Circuit The ICC detects current in the Run circuit but not in the Start circuit of the compressor four (4) times in one compressor call | |
| 7 | 07 – Compressor Open Run Circuit The ICC detects current in the Start circuit but not in the Run circuit of the compressor | |
| L7 | 07 – Compressor Open Run Circuit The ICC detects current in the Start circuit but not in the Run circuit of the compressor four (4) times in one compressor call | |
| 9 | 09 – Low Secondary Volts The secondary voltage at R and C is below 18V AC |
• Control transformer overloaded • Low line voltage |
| 21 | 21 – Low Pressure Control Open The ICC detects the LPC is open. Note: The low pressure control is ignored for the first 90 seconds of compressor operation |
• Unit has low refrigerant charge • Indoor coil is frozen (cooling mode) • Dirty indoor coil or filter (cooling mode) • Indoor blower is not running (cooling mode) • Outdoor coil is frozen (heating mode) • Expansion valve is not operating correctly |
| L 21 FLASHING | L21 – Active Protection Low Pressure Control Trip | LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 21 |
| 27 | 27 – Low Line Voltage or No Line Voltage Fault | • Check incoming line voltage to the disconnect and unit • Check wiring connections |
| 28 | 28 – High Line Voltage Fault | • Check line voltage |
| 29 | 29 – High Pressure Control Open The ICC detects the HPC is open | • Outdoor coil is dirty (cooling mode) • Outdoor fan is not running (cooling mode) • Dirty indoor coil or filter (heating mode) • Indoor blower is not running (heating mode) • Liquid line restriction • Excessive refrigerant charge |
| L 29 FLASHING | L29 – Active Protection High Pressure Control Trip | LPC has opened 3 times in the same cooling operation, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 29 |
| 30 | 30 – Fuse Open | • The 3-amp fuse on the ICC is open. |
| The ICC detects the on-board fuse is open | • Low voltage wiring at R and C is damaged or miswired. | |
| 80 | 80 – Low Air Row The ICC detects that the indoor unit is not providing the minimum airflow requirements. |
• Misapplied/wrong indoor air mover – replace with properly sized unit. |
| 83 | 83 – Condenser Coil Temperature Fault The sensor detects an abnormally low or high coil temperature | • Replace the sensor • Check sensor is installed correctly on control |
| 84 | 84 – Outdoor Ambient Temperature Fault The sensor detects an abnormally low or high outdoor ambient temperature | • Check unit placement – If the outdoor unit is in a high temperature area, wait until the ambient temperature drops and check sensor reading. • Replace the sensor. • Check sensor is installed correctly on control |
| 93 | 93 – Internal Control Fault The control is not functioning properly. | • Check control for proper system operation. • Replace control |
| d1 | dl – No Shared Data | • Replace memory card with correct system information. |
| d3 | d3 – Airflow CFM Mismatch The indoor air mover (air handler/fumace) cannot supply the required airflow for proper system operation | • Misapplied/wrong indoor air mover – replace with properly sized air handler/fumace. |
| D4 | d4 – (Device) Memory Card Invalid for Device The data in the memory card inserted into the control board does not match the data in the control. |
• Check memory card to ensure it matches device • Check if memory card is present |
| d8 | d8 – Old Shared Data System data is obsolete | • If system will not operate, order new memory card to update system information. |
Rheem RKNL 13 Seer Series air troubleshooting
| SYMPTOM | POSSIBLE CAUSE | REMEDY |
| Unit will not run | • Power off or loose electrical connection | • Check for correct voltage at compressor contactor in control box |
| • Thermostat out of calibration-set too high | • Reset | |
| • Failed contactor | • Check for 24 volts at contactor coil – replace if contacts are open | |
| • Blown fuses | • Replace fuses | |
| • Transformer defective | • Check wiring-replace transformer | |
| • High pressure control open (if provided) | • Reset-also see high head pressure remedy. The high pressure control opens at 610 PSIG | |
| • Interconnecting low voltage wiring damaged | • Replace thermostat wiring | |
| Condenser fan runs, compressor doesn’t | • Run or start capacitor failed (single phase only) | • Replace |
| • Start relay defective 9single phase only) | • Replace | |
| • Loose connection | • Check for correct voltage at compressor – check & tighten all connections | |
| • Compressor stuck, grounded or open motor winding open internal overload. | • Wait at least 2 hours for overload to reset. If still open, replace the compressor. |
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| • Low voltage condition | At compressor terminals, voltage must be within 10% of rating plate volts when unit is operating. | |
| • Low voltage condition | • Add start kit components | |
| Insufficient cooling | • Improperly sized unit | • Recalculate load |
| • Improper airflow | • Check – should be approximately 400 CFM per ton. | |
| • Incorrect refrigerant charge | • Charge per procedure attached to unit service panel. | |
| • Air. non-condensibles or moisture in system | • Recover refrigerant, evacuate & recharge, add filter drier | |
| • Incorrect voltage | • At compressor terminals, voltage must be within 10% of rating plate volts when unit is operating. | |
| Compressor short cycles | • Incorrect voltage | • At compressor terminals, voltage must be ± 10% of nameplate marking when unit is operating. |
| • Defective overload protector | • Replace – check for correct voltage | |
| • Refrigerant undercharge | • Add refrigerant | |
| Registers sweat | • Low evaporator airflow | • Increase speed of blower or reduce restriction – replace air filter |
| High head-low vapor pressures | • Restriction in liquid line, expansion device or filter drier | • Remove or replace defective component |
| • Flow check piston size too small | • Change to correct size piston | |
| • Incorrect capillary tubes | • Change coil assembly | |
| • TXV does not open | • Replace TXV | |
| High head-high or normal vapor pressure – Cooling mode | • Dirty condenser coil | • Clean coil |
| • Refrigerant overcharge | • Correct system charge | |
| • Condenser fan not running | • Repair or replace | |
| • Air or non-condensibles in system | • Recover refrigerant, evacuate & recharge | |
| Low head-high vapor pressures | • Defective Compressor valves | • Replace compressor |
| • Incorrect capillary tubes | • Replace coil assembly | |
| Low vapor – cool compressor – iced evaporator coil | • Low evaporator airflow | • Increase speed of blower or reduce restriction – replace air filter |
| • Operating below 65°F outdoors | • Add Low Ambient Kit | |
| • Moisture in system | • Recover refrigerant – evacuate & recharge – add filter drier | |
| High vapor pressure | • Excessive load | • Recheck load calculation |
| • Defective compressor | • Replace | |
| Fluctuating head & vapor pressures | • TXV hunting | • Check TXV bulb clamp – check air distribution on coil – replace TXV |
| • Air or non-condensibles in system | • Recover refrigerant, evacuate & recharge | |
| Gurgle or pulsing noise at expansion device or liquid line | • Air or non-condensibles in system | • Recover refrigerant, evacuate & recharge |
| Circulating air blower & inducer run continuously, compressor will not start | • Manual reset overtemperature control • tripped |
• Reset or replace |
| • Wire loose in limit circuit | • Check wiring |
Rheem RSNM Series air troubleshooting
| SYMPTOM | POSSIBLE CAUSE | REMEDY |
| Unit will not run | • Power off or loose electrical connection • Thermostat out of calibration-set too high • Defective contactor • Blown fuses • Transformer defective • High pressure control open (if provided) • Interconnecting low voltage wiring damaged |
• Check for correct voltage at compressor contactor in control box • Reset • Check for 24 volts at contactor coil – replace if contacts are open • Replace fuses • Check wiring-replace transformer • Reset-also see high head pressure remedy. The high pressure control opens at 450 PSIG • Replace thermostat wiring |
| Condenser fan runs, compressor doesn’t | • Run or start capacitor defective (single phase only) • Start relay defective (single phase only) • Loose connection • Compressor stuck, grounded or open motor winding, open internal overload. • Low voltage condition • Low voltage condition |
• Replace • Replace • Check for correct voltage at compressor – check & tighten all connections • Wait at least 2 hours for overload to reset. If still open, replace the compressor. At compressor terminals, voltage must be within 10% of rating plate volts when unit is operating. • Add start kit components |
| Insufficient cooling | • Improperly sized unit • Improper airflow • Incorrect refrigerant charge • Air, non-condensibles or moisture in system • Incorrect voltage |
• Recalculate load • Check – should be approximately 400 CFM per ton. • Charge per procedure attached to unit service panel • Recover refrigerant, evacuate & recharge, add filter drier • At compressor terminals, voltage must be within 10% of rating plate volts when unit is operating. |
| Compressor short cycles | • Incorrect voltage • Defective overload protector • Refrigerant undercharge |
• At compressor terminals, voltage must be ±10% of nameplate marking when unit is operating. • Replace – check for correct voltage • Add refrigerant |
| Registers sweat | • Low evaporator airflow | • Increase speed of blower or reduce restriction – replace air filter |
| High head-low vapor pressures | • Restriction in liquid line, expansion device or filter drier • Flow check piston size too small • Incorrect capillary tubes • TXV does not open |
• Remove or replace defective component • Change to correct size piston • Change coil assembly • Replace TXV |
| High head-high or normal vapor pressure – Cooling mode | • Dirty condenser coil • Refrigerant overcharge • Condenser fan not running • Air or non-condensibles in system |
• Clean coil • Correct system charge • Repair or replace • Recover refrigerant, evacuate & recharge |
| High head-high or normal vapor pressure – Heating mode | • Low air flow – condenser coil • Refrigerant overcharge • Air or non-condensibles in system • Dirty condenser coil |
• Check filters – correct to speed • Correct system charge • Recover refrigerant, evacuate & recharge • Check filter – clean coil |
| Low head-high vapor pressures | • Flow check piston size too large • Defective Compressor valves • Incorrect capillary tubes |
• Change to correct size piston • Replace compressor • Replace coil assembly |
| Low vapor – cool compressor – iced evaporator coil | • Low evaporator airflow • Operating below 65°F outdoors • Moisture in system • TXV limiting refrigerant flow |
• Increase speed of blower or reduce restriction – replace air filter • Add Low Ambient Kit • Recover refrigerant – evacuate & recharge – add filter drier • Replace TXV |
| High vapor pressure | • Excessive load • Defective compressor |
• Recheck load calculation • Replace |
| Fluctuating head & vapor pressures | • TXV hunting • Air or non-condensate in system |
• Check TXV bulb clamp – check air distribution on coil – replace TXV • Recover refrigerant, evacuate & recharge |
| Gurgle or pulsing noise at expansion device or liquid line | • Air or non-condensibles in system | • Recover refrigerant, evacuate & recharge |
Rheem RA13 Series Air Conditioners troubleshooting
| SYMPTOM | POSSIBLE CAUSE | REMEDY |
| Unit will not run | • Power off or loose electrical connection | • Check for correct voltage at line voltage connections in condensing unit. |
| • Thermostat out of calibration – set too high | • Reset. | |
| • Defective control board | • Check control board diagnostic codes. | |
| • Blown fuses/tripped breaker | • Replace fuses/reset breaker. | |
| • Transformer defective | • Check wiring. Replace transformer. | |
| • High-pressure control open Low-pressure control open | • Reset. Also see high head pressure remedy. The high- pressure control opens at 610 PSIG. | |
| • Miswiring of communications (communication light on continuously) | • Check communication wiring. | |
| Outdoor fan runs, compressor doesn’t | • Run or start capacitor defective | • Replace. |
| • Contactor defective | • Replace. | |
| • Loose connection | • Check for correct voltage at compressor. Check and tighten all connections. | |
| • Compressor stuck, grounded or open motor winding, open internal overload. | • Wait at least 3 hours for overload to reset. If still open, replace the compressor. | |
| • Low-voltage condition | • Add start kit components. | |
| Insufficient cooling | • Improperly sized unit | • Recalculate load. |
| • Improper indoor airflow | • Check. Should be approximately 400 CFM per ton. | |
| • Incorrect refrigerant charge | • Charge per procedure attached to unit service panel. | |
| • Air, noncondensibles, or moisture in system | • Recover refrigerant. Evacuate and recharge. Add filter drier. | |
| • Bad ID TXV | • Replace TXV | |
| Compressor short cycles | • Incorrect voltage | • At compressor terminals, voltage must be ± 10% of nameplate marking when unit is operating. |
| • Defective overload protector | • Replace. Check for correct voltage. | |
| • Refrigerant undercharge | • Add refrigerant. | |
| Registers sweat | • Low indoor airflow | • Increase speed of blower or reduce restriction. Replace air filter. |
| High head, low vapor pressures | • Restriction in liquid line, expansion device, or filter drier | • Remove or replace defective component. |
| • Bad TXV | • Replace TXV. | |
| High head, high or normal vapor pressure – Cooling mode | • Dirty outdoor coil | • Clean coil. |
| • Refrigerant overcharge | • Correct system charge. | |
| • Outdoor fan not running | • Repair or replace. | |
| • Air or noncondensibles in system | • Recover refrigerant. Evacuate and recharge. | |
| Low head, high vapor pressures | • Bad TXV | • Replace TXV. |
| • Bad compressor | • Replace compressor. | |
| Low vapor, cool compressor, iced indoor coil | • Low indoor airflow | • Increase speed of blower or reduce restriction. Replace air filter. |
| • Operating below 65°F outdoors | • Add Low Ambient Kit. | |
| • Moisture in system | • Recover refrigerant. Evacuate and recharge. Add filter drier. | |
| • Closed ID circuit | • Repair or replace ID coil | |
| High vapor pressure | • Excessive load | • Recheck load calculation. |
| • Defective compressor | • Replace. | |
| Fluctuating head and vapor pressures | • TXV hunting | • Check TXV bulb clamp. Check air distribution on coil. Replace TXV. |
| • Air or noncondensibles in system | • Recover refrigerant. Evacuate and recharge. | |
| Gurgle or pulsing noise at expansion device or liquid line | • Air or noncondensibles in system | • Recover refrigerant. Evacuate and recharge. |
| High superheat | Low charge | Check system charge. |
| (greater than 15°F [-9°C] at coil) | Faulty metering device | Restricted cap tube. TEV (TXV) |
| Power element superheat out of adjustment internally | ||
| Foreign matter stopping flow | ||
| Hiyli internal luud | Hoi air (allk;) entering return | |
| Heat source on; miswired or faulty control | ||
| Restriction in liquid line | Drier plugged. | |
| Line kinked. | ||
| Low head pressure | Low charge | |
| Operating in low ambient temperatures | ||
| Suction or liquid line subjected to high heat | Hot attic / insulate liquid line | |
| source | Hot water line | |
| Low line voltage | Loose wire connections | Check wiring. |
| Power company problem, transformer | Have problem corrected before diagnosis continues. | |
| Undersized wire feeding unit | Correct and complete diagnosis. | |
| High line voltage | Power company problem | Have problem corrected. |
| High head pressure | Overcharge | Check system charge. |
| Dirty outdoor coil | Clean coil. | |
| Faulty or wrong size outdoor fan motor | Replace fan motor. | |
| Faulty fan blade or wrong rotation | Replace fan blade. | |
| Replace with correct rotation motor. | ||
| Recirculation of air | Correct installation. | |
| Additional heat source | Check for dryer vent near unit. | |
| Check for recirculation from other equipment. | ||
| Noncondensibles | Recover refrigerant. Evacuate and recharge system. | |
| Equipment not matched | Correct mismatch. | |
| Short cycling of compressor | Faulty pressure control | Replace pressure control. |
| Loose wiring | Check unit wiring. | |
| Thermostat | Located in supply air stream | |
| Differential setting too close | ||
| Customer misuse | ||
| TEV | Internal foreign matter | |
| Power element failure | ||
| Valve too small | ||
| Distributor tube/tubes restricted | ||
| Distributor tube | Restricted with foreign matter | |
| Kinked | ||
| I.D. reduced from previous compressor failure |
Rheem RKNL 13 SEER Air Conditioners troubleshooting
| SYMPTOM | POSSIBLE CAUSE | REMEDY |
| Unit will not run | • Power off or loose electrical connection | • Check for correct voltage at compressor contactor in control box |
| • Thermostat out of calibration-set too high | • Reset | |
| • Failed contactor | • Check for 24 volts at contactor coil – replace if contacts are open | |
| • Blown fuses | • Replace fuses | |
| • Transformer defective | • Check wiring-replace transformer | |
| • High pressure control open (if provided) | • Reset-also see high head pressure remedy. The high pressure control opens at 610 PSIG | |
| • Interconnecting low voltage wiring damaged | • Replace thermostat wiring | |
| Condenser Ian runs, compressor doesn’t | • Run or start capacitor failed (single phase only) | • Replace |
| • Start relay detective 9single phase only) | • Replace | |
| • Loose connection | • Check for correct voltage at compressor – check & tighten all connections | |
| • Compressor stuck, grounded or open motor winding open internal overload. | • Wait at least 2 hours for overload to reset. | |
| • Low voltage condition | II still open, replace the compressor. | |
| • Low voltage condition | At compressor terminals, voltage must be within 10% of rating plate volts when unit is operating. | |
| • Add start kit components | ||
| Insullicient cooling | • Improperly sized unit | • Recalculate load |
| • Improper airflow | • Check – should be approximately 400 CFM per ton. | |
| • Incorrect refrigerant charge | • Charge per procedure attached to unit service panel. | |
| • Air. non-condensibles or moisture in system | • Recover refrigerant, evacuate & recharge, add filter drier | |
| • Incorrect voltage | • At compressor terminals, voltage must be within 10% of rating plate volts when unit is operating. | |
| Compressor short cycles | • Incorrect voltage | • At compressor terminals, voltage must be ± 10% of nameplate marking when unit is operating. |
| • Defective overload protector | • Replace – check for correct voltage | |
| • Refrigerant undercharge | • Add refrigerant | |
| Registers sweat | • Low evaporator airflow | • Increase speed of blower or reduce restriction – replace air filter |
| High head-low vapor pressures | • Restriction in liquid line, expansion device or filter drier | • Remove or replace defective component |
| • Flow check piston size too small | • Change to correct size piston | |
| • Incorrect capillary tubes | • Change coil assembly | |
| • TXV does not open | • Replace TXV | |
| High head-high or normal vapor pressure – Cooling mode | • Dirty condenser coil | • Clean coil |
| • Refrigerant overcharge | • Correct system charge | |
| • Condenser fan not running | • Repair or replace | |
| • Air or non-condensibles in system | • Recover refrigerant, evacuate & recharge | |
| Low head-high vapor pressures | • Detective Compressor valves | • Replace compressor |
| • Incorrect capillary tubes | • Replace coil assembly | |
| Low vapor – cool compressor – iced evaporator coil | • Low evaporator airflow | • Increase speed of blower or reduce restriction – replace air filter |
| • Operating below 65°F outdoors | • Add Low Ambient Kit | |
| • Moisture in system | • Recover refrigerant – evacuate & recharge – add filter drier | |
| High vapor pressure | • Excessive load | • Recheck load calculation |
| • Detective compressor | • Replace | |
| Fluctuating head & vapor pressures | • TXV hunting | • Check TXV bulb clamp – check air distribution on coil • replace TXV |
| Gurgle or pulsing noise at expansion device or liquid line | • Air or non-condensibles in system | • Recover refrigerant. evacuate & recharge |
| Circulating air blower & inducer run continuously, compressor will not start | • Manual reset over temperature control | • Reset or replace |
| • tripped | • Check wiring | |
| • Wire loose in limit circuit |