FIXED my GU100 Eternal tankless, bought in 2014. Its only been a day but this is more than I could find online to fix it.
Lost hot water recently and found E27 error on the front panel. Found out that the company went belly up and so on. Opened it up and it was totally dry inside and according to the error code there was a problem with the mixing valve initializing. Saw a video on Youtube about this and followed the directions to remove the mixing valve assy. It's the white plastic thing with two wiring harnesses attached to the bottom of the gray plastic mixing valve. Easy peasy, 15 minutes. Spent two hours online reading the forums and nearly bought another tank less online. Slept on it. Woke up remembering one simple post about the same control valve motor being used by other companies. Googled the part number on the control unit (NSAE101). Found one online for $55 (Boston Heating Supply
---Sales@bostonheatingsupply.com) The part is listed as follows:
Navien 30011532A Water Adjustment Valve It comes with a mixing valve that you need to take off and put the Eternal part in its place. Put it in and we're back in business.
Note: YOU HAVE TO DISMANTLE THE BAD NSAE101 TO MAKE SURE YOU MATCH THE POSITION OF THE SMALL MAGNET ON THE LARGER GEAR OF THE BAD NSAE101 MOTOR CONTROL UNIT WITH THE NEW NSAE101!
When I first removed the control unit from the mixing valve and took it apart it was full of water and the electronics were probably compromised. The control unit is two halves held together by 4 tabs. I used a small screw driver to pry the tabs back and slipped a piece of 24 gauge wire up into the slot I created when prying apart. With all 4 tabs held out by the wires, the two halves pry apart easily without breaking the tabs.
