In response to zl700 thank you for the parameter list.In response to Dana, Thank you for responding. I have read the manuals thoroughly . Its a shame they do not include a detailed list of the parameters there. I am not clear as to why the cold water sandwich can not be improved. I am using the Navilink and App to set recirculation schedules. Recirculation through my cold water system- no dedicated line.
I will share some of my thinking . please correct me if I am wrong.
P12-- was set to 5 minutes by my installer based on time that it took the pipes to get warm at my farthest fixture. I increased this to six minutes and saw more consistent temperatures at my farthest fixtures.
Theory: At 5 minutes the fixture was getting warm, but with the additional minute more hot water was recirculating back toward the Navien. Essentially warming more of my cold water lines. My shower has a balanced valve so that when open new heated water would now mix with more return line warm water ( In the cold system) stretching out the time frame until the navient burner kicked in again with my demand.... less sandwich.
P14: Theory: I believe The water in my recirculation system cools down pretty quickly. Because my system was installed in existing construction I do not have a dedicated return line and I can not access the existing lines to insulate them.
This parameter appears to tell the unit how often to sample the return line to check for a temperature drop. Default is 30 minutes, but I belive there is is a lot of temperature drop off in that 30 minutes. I have just set this parameter to 15 minutes with the thinking that it will reheat more frequently if it the NPE senses that temp drop.
P15: The text in this parameter is slightly unclear to me-- but as I think as I understand it the the burner will turn off during a recirulation when it sees a specified differential between set temp and return temp. Default differential is 9 degrees. If I set the default to the lowest differential, 5 degrees wouldn't the burner stay on longer ? This is further unclear to me because I belive the Navicirc (and /or Grundfos) valves shut between 85- 90 degrees. If that is the case will the Navien ever see return line samples above this temp? If not then the differential will always be greater than the default or lower. So is this parameter even relevant?
So, Dana, I understand what you are saying about the flue purge and ignition delays being fixed, and I can't add more insulation to my lines, But does the thinking above make any sense in terms of keeping the hottest and most consistent water in my lines at least during a scheduled recirculation?
Thanks.