My Navien NPE240A with Navien hardwired remote (NR-20DU) "short cycles" when in the programed times to circulate. This short cycling always happens at approximately 45-50 minutes into a programed cycle. If I program the length of time to 30 minutes, (the minimum) the flame loss error will not happen. Resetting on the unit always works, but it's not ideal to always have to check. So currently I have the 3 programed time for 30 minutes each. I always have great lengthy hot showers, with only a 3 second delay to get a hot shower. I could shower for 2 hours if desired, so the unit will not flame out while burning to produce a hot shower. A 30 minute programed recirculate time can go weeks without producing an error flame loss (012).
I have a dedicated re-circulation loop, which connects all the hot faucets & showers in this 4000 sq. ft home. I thought perhaps there would be a parameter to tweek, but to my surprise I don't seem to be able to find parameters using the technique of turning the unit off, and hitting the + button 3x's, -button 3's, + button 4x's....this produces the 1.tec menu button, but then hitting + , I have no parameters. Can this even be possible? I found one lone statement on this site that early NPE240a's did not have parameters. Anybody know? My home is a 2008, and I have lived here only 2 years. So I'm not sure if the previous owner used the re-circulation loop, or if they used the unit with internal tank only, and waited 2 minutes for a hot shower.
On the short cycling issue, I did hire a Navien tech out to the home, & with tech on the line, it was decided to replace the dual venturi & the flame rod assembly. Parts & labor cost me $420, and this produced no change. I thought I might ask here for opinions before looking for another tech to help. So thank you in advance for your comments and help. Oh, I am positive my dip switches are correct and the internal valve is set correct. It works as it should, the unit just begins to malfunction 45 minutes into heating the loop. It does flame continuous for 45 minutes....it would seem this is quite lengthy to just raise the loop from approx 70 deg to 125 deg. Anyway, thanks again for listening.
I have a dedicated re-circulation loop, which connects all the hot faucets & showers in this 4000 sq. ft home. I thought perhaps there would be a parameter to tweek, but to my surprise I don't seem to be able to find parameters using the technique of turning the unit off, and hitting the + button 3x's, -button 3's, + button 4x's....this produces the 1.tec menu button, but then hitting + , I have no parameters. Can this even be possible? I found one lone statement on this site that early NPE240a's did not have parameters. Anybody know? My home is a 2008, and I have lived here only 2 years. So I'm not sure if the previous owner used the re-circulation loop, or if they used the unit with internal tank only, and waited 2 minutes for a hot shower.
On the short cycling issue, I did hire a Navien tech out to the home, & with tech on the line, it was decided to replace the dual venturi & the flame rod assembly. Parts & labor cost me $420, and this produced no change. I thought I might ask here for opinions before looking for another tech to help. So thank you in advance for your comments and help. Oh, I am positive my dip switches are correct and the internal valve is set correct. It works as it should, the unit just begins to malfunction 45 minutes into heating the loop. It does flame continuous for 45 minutes....it would seem this is quite lengthy to just raise the loop from approx 70 deg to 125 deg. Anyway, thanks again for listening.