Navien

KD Navien

2 field manuals · 6 error codes · 1 guides

Ask about a Navien
Water HeaterFurnace Model & serial

Navien water heaters

Manual · Water Heater

Navien NPE-A2 condensing tankless (ComfortFlow): quick sheet

Navien NPE-180A2, NPE-210A2 and NPE-240A2 (A2 = built-in buffer tank and recirculation pump, 'ComfortFlow'); the NPE-S2 models (150S2-240S2) are the same generation without ComfortFlow. Earlier NPE-A (first generation) units differ in controls.

6 components3 common failuresNavien
Manual · Water Heater

Gas tankless water heater: field service manual (water side and diagnostics)

Residential non-condensing and condensing gas tankless units with digital controllers

5 components3 common failuresRinnai, Navien, Noritz, Rheem, A.O. Smith, Bradford White

Error codes

E003 Ignition failureE004 False flame detectedE012 Flame loss during operationE016 OverheatingE030 Exhaust overheatE515 Circuit board (PCB) abnormal
Guide · Water Heater

Tankless: error code, no ignition at low flow, or temperature swings

Many tankless complaints are water-side: flow below the activation threshold, a clogged inlet screen, low-flow aerators, or scale in the heat exchanger. Gas supply, venting and combustion codes are blocked: diagnose and refer. Read the code first, then work the water side.

6 steps ~90 minmoderate

Identify a Navien

Where's the rating plate?

  • Water Heater: Rating data plate on the unit.

Reading the model number

Not sourced.

Manufacture date from the serial number

Single source

Common style: characters 6-7 = year (20xx), character 8 = month (1-9, X=Oct, Y=Nov, Z=Dec), then the day.

EXAMPLE ONLY: 1234516X0912345 -> 2016, October, day 09.

Single source; other styles show a 4-digit year inside the serial.

Product lines by era

Line / seriesApplianceYearsNotes
NPE-AWater Heater2012–Condensing tankless with built-in recirculation pump/buffer.
NPE-SWater Heater2013–Condensing tankless, standard (no recirc) version.
NCB combi-boilerFurnace2013–Combination boiler for heat and domestic hot water.
NHB boilerFurnace2014–Heat-only condensing boiler.
NCB-E combi-boilerFurnace2015–Updated combi-boiler series.
H2AirFurnace2017–Combined space heating (air handler) and water heating system.

Official Navien manuals & support

Brand names identify appliances only. OnCall Tech is not affiliated with or endorsed by Navien.