5.2.19 Error 782 High

Navien 5.2.19 Error 782 Fault Code

Also written as 5219ERROR782 — same fault.

The Navien 5.2.19 Error 782 fault code means: your boiler's main internal controller has lost its connection, meaning it cannot receive signals from the display panel to operate your heating and hot water.. It appears on 6 Navien models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Is the wiring from the front panel properly connected to the PCB?
Typical repair cost £120-250 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Navien models that show the 5.2.19 Error 782 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Navien 5.2.19 Error 782 fault code information on this page is sourced and cross-checked against the official Navien service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026