Navien NCB240 E012 possible venting issues?


Old 11-13-17, 01:48 PM
Thread Starter
Join Date: May 2007
Location: MA
Posts: 9
Received 0 Votes on 0 Posts
Navien NCB240 E012 possible venting issues?


I live in MA and had a Navien NCB 240 that is throwing E012 errors almost on a daily basis. It seems to happen often on either colder/windier days. I'm starting to think it may have something to do with the the intake/exhaust piping is setup. Below are pictures of the outside vents.

Gray is the exhaust, White is the intake. Does anyone see any issues with how these are installed?
Attached Images   
Sponsored Links
Old 11-13-17, 09:09 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,518
Received 505 Votes on 475 Posts
I'm not the pro in this forum and especially on Navien boilers. The E012 is a generic flame loss code. There seems to be several things that routinely cause it. Number one is gas pressure when operating.

I see the exhaust is close to the chimney. I'm guessing the wind could trap the exhaust gases there and the intake draws them in. You could try temporarily adding a short piece of PVC pipe to the intake line to get it away from the wall and see it that changes anything.

Name:  navien.JPG
Views: 1413
Size:  33.9 KB

Check out these threads....

Old 11-14-17, 09:43 AM
Join Date: Jan 2014
Location: USA near Boston, MA
Posts: 708
Received 23 Votes on 19 Posts
Rather than turn the intake down, I suggest you turn the exhaust up with a tee or elbow at the top. Your vents are close to the ground now and could become blocked by drifting snow, especially in the corner formed by the brick chimney. Blocked intake/exhaust will cause deadly carbon monoxide to build up in the house.

Massachusetts law requires a bright yellow sign warning of this danger to be mounted on the wall 8 feet above the vents.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: