Product type	Where to look
Heating, Cooling & Air	Thermostats show the model on the back of the faceplate or in the settings menu. Window units put the label on the side of the cabinet. Purifiers and dehumidifiers put it on the base or back.

Getting the official Navien manual

Navien publishes product documentation on navieninc.com. Search there with the full model number from the label, then look for a documents, manuals or downloads section on the product page.

If your model isn't listed, try removing the last few characters, which usually only indicate color or region. For discontinued models, look for an archive or legacy products section, or contact Navien support directly.