Navien Tankless Hot Water Maintenance

[@clady2000]

Hello, I just watched your video, very informative. I also have the very same model NPE-240A2. It's fairly new, just installed February 2022. Today, my Navien went into "standby" mode and I can't get it out of this mode. I've search on the internet, and did the reset on the control panel, by pressing the "back" button, nothing happened. Then I cut it off at the breaker box, first for a few minutes...no change. Then I turned off the breaker for 30 min...again, no change. I then turned of the breaker for 2 hours....again, no change....still in "standby" mode. I read the possible issues that this unit may go into "standby" mode, however, I am a single person household and live alone. No real hot water used earlier today, as I noticed the issue just before I ran the dishwasher late this afternoon and ever since. I can't get the hot water to heat or get the unit out of the "standby" mode. Do you have any pointers or anything else I can do to get this working again? I would love to get enough hot water to take a shower before tomorrow's doctors appointment! This is my 2nd Navien tankless, and I've never had this issue before. Any help would be appreciated and I'm a pretty diy'er, even in my 60's! Thank you for your time and help with this problem.....Norma

[@Subariblet]

It sounds like you’ve done everything you are supposed to do. I would check to make sure that the temperature is set at 120 or 125. When the unit is in standby, it’s waiting to detect water running through it and it tells the burners to ignite. It should only take a few seconds. If you turn your hot water on and cold water keeps flowing out and the unit doesn’t turn on, then you have a different problem. It will be a problem with something on the inside like a flow sensor or something computer related.

[@danmc5394]

Any suggestions on how to flush the unit when there are extra connections for in-floor heat?