Navien Error Code E593: Abnormal Panel Key
How to Fix Navien Code E593
- Step 1: Inspect the control panel for any visible signs of damage, moisture, or debris. Clean the panel gently with a dry cloth.
- Step 2: Try pressing each button on the control panel individually to see if any feel stuck or unresponsive. Sometimes, repeatedly pressing a button can dislodge it if it's slightly stuck.
- Step 3: If the error persists after cleaning and checking the buttons, contact a qualified HVAC technician to diagnose and repair the unit.
How to Reset Navien Code E593
- Turn off the unit using the power button on the front panel.
- Turn off the gas supply valve.
- Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
- Restore power at the breaker, then open the gas valve.
- Turn the unit back on. If the error returns, the underlying issue needs repair.
What does E593 mean?
The E593 error code on your Navien tankless water heater or combi-boiler indicates an abnormal panel key input. Basically, the unit's control board is receiving unexpected or incorrect signals from the buttons on the front panel. This could be due to a stuck button, a short in the wiring, or a problem with the control board itself. When this happens, the unit shuts down as a safety measure to prevent unintended operation or damage. You'll likely notice a lack of hot water or heating, depending on your Navien model.
This error is important because it prevents the unit from operating correctly and could potentially lead to further issues if left unaddressed. While some causes are minor, others can point to a more significant electrical problem within the unit. It's best to troubleshoot this issue to get your Navien back up and running reliably.
Affected Models
- NCB-H
- NFB-H
- NFC-H
- NHB-H
- NHW-A
- NPE-A2
- NCB
- NCB
- NCB
- NPE
- NPE
- NPE
- NHB
- NHB
- NCB
- NCB
- NPE
- NPE
- NCB
- NCB
- NPE
- NCB
- NPE
- NHB
- NCB
- NPE
- NPE
- NCB
- NCB
- NPE
- NPE
- NPE
- NPE
- NHB
- NHB
- NCB
- NCB
- NPE
- NPE
- NBP
- NPE
- NPE
- NPE
- NFC
- NFC
- NCB
- NPE
- NPE
- NPE
- NCB
- NPE
- NCB
- NPE
- NPE
- NCB
- NPE
- NHB
- NPE-S
- NPN
- NPN
- NCB
- NPE
- NCB
- NPE
- NHB
- NPB
- NFC
- NFC
- NHB
- NPF
- NPF
- NPE
- NHB
Source Documentation
| Manual | Page | Reason | Action |
|---|---|---|---|
| Navien NPF Installation & Operation Manual | 127 | Abnormal Panel Key | This error occurs when the buttons on the front control panel do not operate properly. ● If this error occurs continuously, contact Technical Support at 1-800-519-8794. |
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Front Control Panel | — | — |
| Main Control Board | 30010647A | — |
| Ribbon Cable | — | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| E001 | Ignition Failure | Warning |
| E003 | Abnormal Ignition | Warning |
| E004 | False Flame Detection | Warning |
| E012 | Flame Loss | Warning |
| E016 | Overheating | Warning |
| E030 | Exhaust Overheat Sensor | Warning |
| E031 | Inlet Thermistor Open/Short | Warning |
| E046 | Outlet Thermistor Open/Short | Warning |
| E047 | DHW Thermistor Open/Short | Warning |
| E060 | Fan Motor Abnormality | Warning |