What does the Navien E127 fault code mean?

Your boiler's air pressure sensor is failing to detect the correct airflow, meaning the unit has shut down to ensure safe operation.

How much does it cost to fix Navien error code E127?

Typical repair cost for the Navien E127 fault is £150-300 including labour.

APS error (open, short, initial value or no response)

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Six most common causes of dropping pressure.

Each noise points to a different fault.

Safety-critical — turn off, read this.