Navien NPE-240A Service Manual

Version 2.21
20 NPE Service Manual
4.2 Operation Flow Chart
IG : Igniter
MGV1 : Main Gas valve 1
MGV2 : Main Gas valve 2
NO
Ye
s
Flow sensor
≥ 0.53 gpm
120v Power
Applied
System
Initialization
Displays version
Standby Mode
Fan start-up &
Fan control
Stage 1 or
Stage 2 ?
Dual venturi OFF
Stage 1
Dual venturi ON
Flame ON?
Yes
IG OFF
Flame check time
> 3 sec
Burner Operation
Flow sensor
≤ 0.48 gpm
NO
NO
Yes
MGV1 OFF
MGV2 OFF
Post Purge
Fan Stop
Yes
Stage 2
NO
IG ON
MGV1 ON
MGV2 ON

Navien NPE-240A Specifications

General

Type	Tankless
Fuel Type	Natural Gas or Propane
Energy Factor	0.97
Energy Efficiency	97%
Voltage	120V
Ignition Type	Electronic
Maximum Input	199, 900 BTU/h
Water Connection Size	3/4"
Gas Connection Size	3/4"
Warranty	15-year on heat exchangers, 5-year on parts, 1-year on labor
Dimensions	17.3" W x 13.2" D x 27.4" H