Navien Error Code E810: Abnormal circulator operation (inoperable)
How to Fix Navien Code E810
- Step 1: Turn the unit off and then back on again. This may reset the system and clear a temporary error.
- Step 2: Check the system pressure on the unit's display. Low water pressure can sometimes cause circulation issues. Ensure it's within the normal operating range (typically 15-20 PSI).
- Step 3: If the error persists after resetting and checking pressure, contact a qualified HVAC technician for diagnosis and repair.
How to Reset Navien Code E810
- 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.
Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.
What Does Navien Error Code E810 Mean?
The E810 error code on your Navien tankless water heater indicates an issue with the circulator pump. This pump is responsible for moving water through the heat exchanger, allowing it to be heated efficiently. When the control board detects that the pump isn't operating correctly, it shuts down the unit to prevent overheating or damage. This can happen due to a pump failure, blockage in the system, or an electrical problem. Without proper circulation, the water heater can't heat water effectively, and the high limit switch may trip. This error often requires a technician to diagnose the root cause and replace the faulty component. Ignoring this error can lead to further damage to the unit and a prolonged period without hot water.
Common Causes
- Failed or failing circulator pump. The pump motor may be seized or have an electrical fault.
- Air lock in the system preventing the pump from priming and circulating water.
- Debris or scale buildup within the pump housing, impeller, or piping restricting water flow.
- Wiring issue between the control board and the circulator pump. Loose connections or damaged wires can interrupt the signal.
- Faulty control board not sending the correct voltage to the pump.
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| Circulator pump is not running | Voltage at the circulator pump terminals | 120VAC when the unit is calling for heat |
| Voltage is present at the pump | Resistance of the circulator pump motor windings | Specific resistance value according to the Navien service manual (check against a known good pump if possible) |
| Pump is receiving voltage but not running | Inspect the pump impeller for debris or scale buildup | Impeller should be free of obstructions and able to spin freely |
| Wiring appears damaged | Continuity of wiring harness between the control board and the circulator | Full continuity, no breaks in the wire |
Applicable Navien Models
Source Documentation
Referenced in 1 official Navien technical manual.
| Manual | Page | Reason | Action |
|---|---|---|---|
| Navien NPF Installation & Operation Manual | 129 | Abnormal circulator operation (inoperable) | This error occurs when the ECM Motor is inoperable. ● Check the filter’s status. ● Check the SA or RA ducts. ● Check if foreign substances are inside the furnace. ● Turn off the furnace, turn it on again, and check if the furnace operates properly. ● If this error occurs continuously, contact Technical Support at 1-800-519-8794. |
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Circulator Pump | — | — | — |
| Main Control Board | — | — | — |
| Flow Sensor | — | — | — |
Related Codes on Same Models
Other codes that affect the same Navien model families as E810.
| Code | Description | Severity |
|---|---|---|
| E001 | Ignition Failure | Warning |
| E003 | Abnormal Ignition | Warning |
| E004 | False Flame Detection | Warning |
| E031 | Inlet Thermistor Open/Short | Warning |
| E046 | Outlet Thermistor Open/Short | Warning |
| E110 | Exhaust Blocked | Warning |
| E205 | Water Flow Sensor Failure | Warning |
| E517 | Water Flow Switch Failure | Warning |
| E736 | CH Return Thermistor Failure | Warning |
| E740 | CH Buffer Tank Thermistor | Warning |