Navien NPE-240A Service Manual

Version 2.21
92 NPE Service Manual
Check method
Fault Possible Causes Check method
Heat exchanger
overheated
Damaged or clogged
heat exchanger
1. The error occurs due to high exhaust gas temperature caused by a damaged or
clogged heat exchanger.
2. Flush the heat exchanger to remove scale deposits.
3. Replace the heat exchanger if it is damaged or cannot be unclogged.
Defective part
Defective overheat
controller
Defective contact point of the exhaust gas overheat controller 230°F (110°C) Max
●
Check connection of the overheat controller.
●
If the resistance is abnormal, replace the temperature sensor. (refer to page 60)
●
Check the output temperature displayed on the PCB.
Check if the hot water temperature sensor is open (Error type : M Open)
Other trouble Defective PCB If the issue continues despite checking the items above, replace the PCB.

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