Navien Error Code E480: BMS Communication Error

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $100 — $250 (parts + labor)
Warning: Your Navien boiler is experiencing a BMS communication error, which may affect its performance and require professional repair.

How to Fix Navien Code E480

  1. Check for any visible damage to the wiring harness connecting to the BMS
  2. Ensure all sensors are securely connected and free from debris
  3. Contact a professional HVAC technician for further diagnosis and repair

How to Reset Navien Code E480

  1. Turn off the unit using the power button on the front panel.
  2. Turn off the gas supply valve.
  3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
  4. Restore power at the breaker, then open the gas valve.
  5. 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 E480 Mean?

If you're seeing the E480 error code on your Navien boiler's digital display, it means there's a communication issue between the boiler's main control board (BMS) and other components. This could be due to a faulty sensor, wiring issue, or software glitch. While it's not an immediate safety hazard, it's important to address this issue to prevent further system damage or reduced efficiency.

Common Causes

  • Faulty temperature or pressure sensor
  • Wiring issue between BMS and other components
  • Outdated or corrupted BMS software

Diagnostic Steps

If... Check Expected
Boiler is not heating Temperature sensor readings Normal temperature readings
Pressure readings are abnormal Pressure sensor Normal pressure readings

Applicable Navien Models

Source Documentation

Referenced in 3 official Navien technical manuals.

ManualPageReasonAction
NFB-H Installation & Operation Manual116DHW Tank Sensor Not DetectedCheck sensor connections.
Navien NFB-H Installation & Operation Manual116DHW Tank Sensor Not DetectedCheck sensor connections.
Navien NHB-H Installation & Operation Manual119DHW Tank Sensor Not DetectedCheck sensor connections.

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Temperature Sensor
Pressure Sensor

Related Codes on Same Models

Other codes that affect the same Navien model families as E480.

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