RUUD ERROR CODES
Data Verified: January 2026
Professional diagnostic codes and troubleshooting steps.
Technical Note: RUUD systems are part of a shared manufacturing platform. These codes are identical for RHEEM.
Critical Severity
57
A2L Refrigerant Leak Detected
Troubleshooting Steps
- • A2L SAFETY: The system has detected a concentration of R-454B. Blower will run at high speed to disperse gas.
- • Immediately ventilate the indoor area and keep spark sources away.
- • Check the A2L sensor in the indoor coil cabinet for a trip status.
- • Use an A2L-compliant leak detector to find the source of the leak.
Source Reference Rheem Endeavor Service Manual
High Severity
15
Compressor Discharge Temperature Protection
Troubleshooting Steps
- • Check for low refrigerant charge (system is running too hot).
- • Verify the outdoor electronic expansion valve (EEV) is moving and not stuck.
- • Inspect the outdoor coil for heavy dirt or debris blockage.
Source Reference Rheem Endeavor Service Manual
Normal Severity
20
Outdoor Ambient Thermistor Failure
Troubleshooting Steps
- • Check the ambient sensor wiring for damage (common for weed-whacker damage).
- • Verify resistance: 10k Ohms at 77°F.
- • The system will default to a fixed ambient temperature until fixed.
Source Reference Rheem Endeavor Service Manual
High Severity
39
DC Fan Motor Fault
Troubleshooting Steps
- • Check for physical obstructions (ice, branches) in the fan blade.
- • Inspect the 5-pin wiring harness between the motor and the control board.
- • Measure DC voltage at the motor plug; if voltage is present but motor doesn't spin, replace motor.
Source Reference Rheem Endeavor Service Manual
Medium Severity
41
Compressor Discharge Thermistor Failure
Troubleshooting Steps
- • Inspect the sensor located on the compressor discharge line.
- • Verify the sensor has not slipped out of its thermal sleeve.
- • Check for a short or open circuit in the sensor lead.
Source Reference Rheem Endeavor Service Manual
Critical Severity
82
Compressor Over-Current Protection (Inverter)
Troubleshooting Steps
- • Check the compressor windings for a short to ground.
- • Verify the power supply voltage is not sagging under load.
- • Check for a locked rotor (seized compressor).
Source Reference Rheem Endeavor Service Manual
High Severity
93
Compressor Phase Loss / Start-up Failure
Troubleshooting Steps
- • Check the U, V, W wiring between the inverter and compressor.
- • Inspect the inverter board for visible burn marks or failed capacitors.
- • Verify the compressor resistance across all three pins is equal.
Source Reference Rheem Endeavor Service Manual
Critical Severity
26
Line and Neutral Reversed
Troubleshooting Steps
- • ELECTRICAL SAFETY: The furnace has detected that the hot and neutral wires are swapped.
- • Check the polarity at the service switch and the main breaker panel.
- • Verify the furnace is properly grounded (Common cause for false polarity trips).
Source Reference Rheem Endeavor Service Manual
High Severity
61
Blower Motor Fault (No Communication)
Troubleshooting Steps
- • Check the 16-pin or 4-pin harness to the variable speed blower motor.
- • Verify the motor is receiving high-voltage power.
- • Ensure the control board's blower relay is engaging.
Source Reference Rheem Endeavor Service Manual
Critical Severity
26
Line and Neutral Reversed
Troubleshooting Steps
- • ELECTRICAL SAFETY: The furnace has detected that the hot and neutral wires are swapped.
- • Check the polarity at the service switch and the main breaker panel.
- • Verify the furnace is properly grounded (Common cause for false polarity trips).
Source Reference Rheem Endeavor Service Manual
High Severity
61
Blower Motor Fault (No Communication)
Troubleshooting Steps
- • Check the 16-pin or 4-pin harness to the variable speed blower motor.
- • Verify the motor is receiving high-voltage power.
- • Ensure the control board's blower relay is engaging.
Source Reference Rheem Endeavor Service Manual
High Severity
41-13
Electronic Expansion Valve (EEV) Coil Fault
Troubleshooting Steps
- • Measure the resistance of the EEV motor coils (typically 40-50 ohms per phase).
- • Check the 6-pin EEV connector for moisture or corrosion.
- • Verify the EEV 'clicks' during the system power-up initialization sequence.
Source Reference Rheem Endeavor Service Manual
High Severity
10-15
High Pressure Switch Trip
Troubleshooting Steps
- • Check for a dirty outdoor coil or a failed outdoor fan motor.
- • Ensure the service valves are fully open.
- • Verify the system is not overcharged with refrigerant after a recent service.
Source Reference Rheem Endeavor Service Manual
High Severity
11
Failed Ignition (3 Retries)
Troubleshooting Steps
- • Verify the gas valve is in the 'ON' position and gas pressure is sufficient.
- • Check if the hot surface igniter is glowing orange during the start sequence.
- • Ensure the burner ports are not clogged with spider webs or rust.
Source Reference Rheem Diagnostic Codes
Critical Severity
33
Roll-Out Switch Open
Troubleshooting Steps
- • FIRE SAFETY: Flames have 'rolled out' of the burner box. Check for a cracked heat exchanger.
- • Inspect for a blocked flue or vent pipe preventing exhaust flow.
- • Check the physical rollout switch for a manual reset button (usually located near the burners).
Source Reference Rheem Diagnostic Codes