Navien NPE-240A Service Manual

Troubleshooting 77
Scenario2
Check the flame rod Power OFF the unit
Check connector
Check that gas valve is open or
check LP supply
Check the voltage between #1 and #3 of CON 4:
22-24 VDC
Check the voltage between #2 and #3 of CON 4:
22-24 VDC
(see page 52 for Wiring Diagram)
In case of LP gas model, low gas pressure can cause
“Ignition Failure”.
* Normal gas pressure: 8.0 - 13.0" w. c.
NO NO
NO
Yes
Yes
Yes
Is gas valve operating
normally?
Does the main
gas valve have proper
v
oltage?
Is gas valve open?
Scenario3
Restart unit
Check connector
(#1 of CON10)
Clean or replace the flame rod
Check whether ground circuit is
properly installed.
Check the current #1 of CON 10: 1 - 20A
(see page 52 for Wiring Diagram)
NO NO
YesYes
Is the flame detection
device normally
operating?
Is the flame current
detected?

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