Boiler will not start at all, display is blank
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Turn off power at the breaker before opening the electrical compartment. Only qualified persons should work on live circuits.
- Step 1 – Check breaker and switch: Verify the circuit breaker is on and the boiler's service switch is in the ON position.
- Step 2 – Inspect power connections: Remove the electrical cover and check that line and neutral wires are securely connected at the terminal block.
- Step 3 – Check internal fuse: Locate and inspect any internal fuses on the PCB or power supply. Replace only with identical type and rating.
- Step 4 – Test transformer: A technician can measure secondary voltage from the transformer or power supply module. Replace if no output is present.
If the display remains blank after these checks, the main PCB may need replacement by a Navien‑authorized technician.
Repair Difficulty
Required Part
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