

CO alarm went off in the house from the tankless, I think the oily condensate inside the tankless is a sign that this is burning exhaust
CO alarm went off at the house and confirmed by fire department. Disconnected the tankless and the CO dropped from over 50 ppm to traceless.
Opened up the Navian NPE-240A2 and oily condensate all over the plastic on the bottom of the condensing heat exchanger and the plastic at the exhaust port it looks like Ditty threw a party.
Going to call Navian tomorrow as it should be in warranty. Is there a typical point where these heat exchangers fail?
Exhaust is piped proper to code outside, and with the oil I think it's in taking a mix of fresh and exhaust and creating the elevated CO level. I am going to bubble leakcheck at the exhaust port interface tomorrow.
This is in the garage, with garage air intake and exhausts outside where there is no close window. The wired plart is that the firefighters read no CO in the garage, but read the 50ppm where the exhaust from outside has to travel through an open window that is upstairs and offer a bit. I suspect the wind was just right to carry it the CO back inside as a household member was taking a 45 min shower.
Checking to see if I am in the right path and carrying around CO meter that will read 30 ppm while working on this.