Navien · Tankless water heater

Error icon Error indicator

Normal status Navien NPN

What the display is showing

Front-panel indicator that lights when an error exists; an error code then appears on the display. Use the Reset button to reset the heater after an error.

Applies to: NPN-160U/180U/199U, NPN-120E/160E/180E/199E

Settings for these units

Installation clearances (indoor / outdoor) · Navien NPN

SideIndoor: combustiblesIndoor: non-combustiblesOutdoor: combustiblesOutdoor: non-combustibles
Top6 in. (152 mm)2 in. (51 mm)12 in. (305 mm)2 in. (51 mm)
Back0 in.0 in.0 in.0 in.
Front6 in. (152 mm)6 in. (152 mm)Panel 24 in. (610 mm); exhaust 24 in. (610 mm)Panel 0 in.; exhaust 24 in. (610 mm)
Sides2 in. (51 mm)1/2 in. (13 mm)6 in. (152 mm)1/8 in. (3.2 mm)
Ground / bottom12 in. (305 mm)12 in. (305 mm)12 in. (305 mm)2 in. (51 mm)
Vent0 in.0 in.--

Room temp must stay between 32 F (0 C) and 120 F (49 C).

Outdoor models need a weather-rated disconnect switch for the 120 V supply.

Models that show this code

7 models in Navien NPN

NPN-120ENPN-160ENPN-160UNPN-180ENPN-180UNPN-199ENPN-199U

Other codes on the same units

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Source: Navien NPN-U/NPN-E Installation Manual, 2.4 The Front Panel, p.8. Summarized in our own words; check the original manual for your model.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.