Navien E109 (fan motor): what to check

Navien display

E109

“Abnormal operation: fan motor”

NPE-A2, NPE-S2, NPN · NPE-2 User's Information Manual, p. 17; NPN User's Information Manual, p. 22
Owner checks, then technician

What it means

E109 is Navien’s code for “Abnormal operation: fan motor”. What the owner can do depends on the series: the NPE-2 table points to the air intake filter NPE-2 User’s Information Manual, p. 17, while the NPN table sends you straight to Navien Technical Support NPN User’s Information Manual, p. 22.

Check these first

1. Reset the heater once. Press Back on NPE-A2 and NPE-S2 models NPE-2 User’s Information Manual, p. 10. On NPN models press Reset on the front panel, or OK on the remote for outdoor models NPN User’s Information Manual, pp. 12, 21.
2. On an NPN, that is the only owner step the manual gives. If E109 comes back, call Navien Technical Support at 1-800-519-8794 NPN User’s Information Manual, p. 22.
3. On an NPE-A2 or NPE-S2, clean the air intake filter NPE-2 User’s Information Manual, p. 14. First turn the heater off with the Power button and disconnect its power supply; the front cover must not come off while the heater has power p. 6.
4. Remove the front cover, take out the screw that holds the filter at the top left, and pull the filter out. Clean it with a toothbrush and clean running water and let it dry completely p. 14.
5. Put the filter back, secure it with the screw, refit the front cover, reconnect power and switch the heater on p. 14. Do not run the heater with the cover off NPE-2 User’s Information Manual, p. 5.
6. If E109 returns with a clean filter, call an authorized technician, a licensed professional or Navien Technical Support NPE-2 User’s Information Manual, p. 16.

On NPE-2 models a clogged air intake filter also stops the heater with E110, and Navien recommends cleaning the filter every 3–4 months NPE-2 User’s Information Manual, p. 14.

When to call a licensed technician

• E109 on any NPN model, after one reset NPN User’s Information Manual, p. 22.
• E109 on an NPE-2 that returns after the filter is cleaned.
• The fan, its motor and everything else behind the front cover except the NPE-2 air intake filter. Navien tells owners not to repair or replace parts the user’s manual does not recommend NPE-2 User’s Information Manual, p. 6; NPN User’s Information Manual, p. 6.

For NPE-A2 and NPE-S2 heaters, the installation manual says all repairs need pre-authorization from Navien Technical Support, which your installer or a licensed professional calls at 1-800-519-8794, Option 2, from the installation site NPE-2 Installation & Operation Manual, p. 145. The NPN user’s and installation manuals do not include this requirement.

Notes for different models

The Navien tables differ on this code. The NPE-2 user’s manual and the NR-21DU remote manual both say to clean the intake air filter; the remote manual refers to “the Operation manual” without a page number NPE-2 User’s Information Manual, p. 17; NR-21DU Remote Controller Manual, p. 31. The NPN user’s manual lists only a call to Technical Support p. 22, and the NPN manuals describe no air intake filter.

Related Navien codes

• E110 “Abnormal air pressure”
• E012 “Flame loss”

All Navien codes

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