Long shot but hoping someone else might've experienced this... I bought a house with 2 NPE 240s connected in the basement, with a NR-20DU controller that I hoped to reset to modify the recirculation timing, etc., but the controller just blinks red and green light like it is in a fault or something (and flashes "V.11"). Thinking maybe the controller was dead, I tried ordering a replacement controller, and they sent me the wrong one, NR-21DU, but it actually does the same thing when I hooked it up (and when I called, Navien explained I need the 20DU)... So I'm trying to find another 20DU online, but I'm not convinced it won't do the same thing - am I missing something? Or is it possible to use the NaviLink Lite with a NPE 240 (doesn't seem like it)?? Thanks!