Navien Error Code E782: Internal PCB Fault

Severity
Warning
Type
digital display
Where to look
front panel
Estimated repair cost: $300 — $650 (parts + labor)
Warning: Your Navien boiler has detected an internal PCB fault. It's safe to use, but needs professional repair.

How to Fix Navien Code E782

  1. Turn off the boiler at the main power switch for 30 seconds, then turn it back on. If the error persists, proceed to the next step.
  2. Contact a licensed HVAC technician for repair. Do not attempt to open the boiler or fix the issue yourself.

How to Reset Navien Code E782

  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.

What does E782 mean?

The E782 error on your Navien boiler indicates a fault with the internal Printed Circuit Board (PCB). This is the brain of your boiler, controlling its operations. The fault could be due to a software issue, a damaged component, or a problem with the PCB itself. The boiler will continue to function, but the fault needs to be addressed to prevent further issues.

Affected Models

Source Documentation

ManualPageReasonAction
NFB-H Installation & Operation Manual 116 Front Panel Communication Check panel connections.
Navien NCB-H Installation & Operation Manual 130 Front Panel Communication Contact technical support at 1-800-519-8794.
Navien NFB-H Installation & Operation Manual 116 Front Panel Communication Check panel connections.
Navien NFC-H Installation & Operation Manual 128 Abnormal operation: panel communication Alarm
Navien NHB-H Installation & Operation Manual 119 Front Panel Communication Check panel connections.
Navien NPF Installation & Operation Manual 128 Abnormal operation: Controller-Panel communication This error occurs when the controller and panel are not communicated properly. ● Check if the front control panel is connected to the controller properly.

Replacement Parts

PartOEM NumberEst. Cost
PCB Assembly

Related Codes on Same Models

CodeDescriptionSeverity
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