Navien Error Code E890: Abnormal circulator communication
How to Fix Navien Code E890
- Step 1: Turn the unit off and then back on again. This might reset the system and clear the error temporarily.
- Step 2: Check the wiring around the circulator pump for any obvious damage or loose connections. Do not touch any wires, just visually inspect.
- Step 3: If the error persists after restarting, contact a qualified HVAC technician to diagnose and repair the problem.
How to Reset Navien Code E890
- 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 E890 Mean?
The E890 error code on your Navien unit indicates that the main control board isn't communicating properly with the circulator pump. The circulator pump is responsible for moving water through your heating system or to your faucets. Without communication, the system doesn't know if the pump is running correctly, and it shuts down as a safety measure. This can happen due to wiring issues, a faulty pump, or problems with the main control board itself. Basically, the 'brains' of the unit can't talk to the 'muscle' that moves the water.
Common Causes
- Loose or damaged wiring between the main control board and the circulator pump.
- Failed circulator pump.
- Defective main control board.
- Electrical interference affecting the communication signal.
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| Unit displays E890 error | Measure voltage at the circulator pump connector on the main control board during a call for heat. | Nominal voltage (typically 24V DC) present. |
| No voltage at the circulator pump connector | Check the wiring harness between the main board and the pump for continuity and shorts. | No shorts, and good continuity on all wires. |
| Wiring is good, but still no voltage | Check the resistance of the circulator pump motor windings. | Resistance within the manufacturer's specified range (consult Navien service manual). |
| Circulator pump windings test OK, and wiring is good | Replace the main control board. | E890 error clears and the circulator pump operates normally. |
Applicable Navien Models
Source Documentation
Referenced in 1 official Navien technical manual.
| Manual | Page | Reason | Action |
|---|---|---|---|
| Navien NPF Installation & Operation Manual | 129 | Abnormal circulator communication | This error occurs when the cables to the ECM motor are not connected properly. ● 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 | — | — | — |
| Wiring Harness | — | — | — |
Related Codes on Same Models
Other codes that affect the same Navien model families as E890.
| 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 |