UPDATE 2: Okay, I think the fixture distance setting might have solved my initial issue. But here's what I'm now dealing with... Should the internal buffer tank still be working when externally circulating with the internal pump? Because immediately after triggering a recirc cycle, if I go to the farthest fixture and open the hot, i do have hot water, but then I get a cold water sandwich. Which suggests that when the heater kicks back on (because I've opened the hot tap), it's sending some cold water out before the burner ignites. But isn't this exactly what the buffer tank is designed to prevent? Are these two systems designed to work in tandem so you get the best of both worlds?
UPDATE: My post hasn't even been approved yet, but have got some more info to share. I kept digging and found some more posts here that speak to this issue. There's another param that sets the distance of the furthest fixture, and it's defaulted to 30ft. Odd that this param isn't mentioned in the button manual. I increased it to 100ft just as a test (I remember my plumber saying it's actually about 60ft), and yeah it's definitely running longer. But on a couple of tests, it ran only for a few seconds again. That would make sense if it were detecting the copper return line was already hot, but in this particular test, it wasn't. It was still room temp at best. I guess I'll keep trying different settings. Might also be a good idea to just install the temp sensor at the farthest fixture, since that's the most accurate way to run the pump.
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This topic has been discussed before and in my case, this post in particular. But there weren't any replies and OP seemed to solve it on his own...
Moved into this house last year, it already had a ~2yr old Navien NPE-240A installed, but with no external recirc line. I had my plumber run the line a few months ago and we set it to the normal external recirc mode, Intelligent mode disabled. That was fine...a noticeable difference, but still not optimal, so I flipped the dip switch to try out Intelligent mode. It was way worse. We have odd schedules so it never really seemed to learn.
Decided to order the PZZZ-00046 hot button kit and hook it up to a dry contact relay controlled by Home Assistant, inspired by this post. It was easy to install, no issues. Checked the params in the settings, as described in the install manual...they were as expected. Recirc cycle time (P. 12) set to 5m. I didn't install the included temp sensor, as it says it's optional and I just wanted to get it working generally before deciding whether I want that or not.
But it just doesn't seem to be working right. Closing the relay doesn't always cause the Navien to react (which I suppose is expected, because apparently there's internal logic to prevent a cycle within X minutes of a previous cycle or hot water being used at all)...but on the occasions where it does react, here's what happens...
1. I hear the Navien spring into action
2. The recirc and burner symbols light up
3. I feel water just barely starting to move thru the return line
4. 2-3 second later, everything stops and the Navien returns to inactive
That's it. Nothing else happens. And the return line is still cold.
I read multiple posts talking about the Energy Saver mode controlled by the #2 dip on the hot button board. Mine has the solder points, but no switches. So I soldered #2, re-installed it. No change in behavior at all. And I'm not even convinced that was the issue, anyway. Because Energy Saver mode is supposed to restrict the cycle to 30 seconds, not 3.
This can't be correct, right? What is causing it to seemingly start a recirc cycle and then immediately shut down?
The Navien is working perfectly normal otherwise. Calling for hot water from any faucet continues to work fine.
UPDATE: My post hasn't even been approved yet, but have got some more info to share. I kept digging and found some more posts here that speak to this issue. There's another param that sets the distance of the furthest fixture, and it's defaulted to 30ft. Odd that this param isn't mentioned in the button manual. I increased it to 100ft just as a test (I remember my plumber saying it's actually about 60ft), and yeah it's definitely running longer. But on a couple of tests, it ran only for a few seconds again. That would make sense if it were detecting the copper return line was already hot, but in this particular test, it wasn't. It was still room temp at best. I guess I'll keep trying different settings. Might also be a good idea to just install the temp sensor at the farthest fixture, since that's the most accurate way to run the pump.
--
This topic has been discussed before and in my case, this post in particular. But there weren't any replies and OP seemed to solve it on his own...
Moved into this house last year, it already had a ~2yr old Navien NPE-240A installed, but with no external recirc line. I had my plumber run the line a few months ago and we set it to the normal external recirc mode, Intelligent mode disabled. That was fine...a noticeable difference, but still not optimal, so I flipped the dip switch to try out Intelligent mode. It was way worse. We have odd schedules so it never really seemed to learn.
Decided to order the PZZZ-00046 hot button kit and hook it up to a dry contact relay controlled by Home Assistant, inspired by this post. It was easy to install, no issues. Checked the params in the settings, as described in the install manual...they were as expected. Recirc cycle time (P. 12) set to 5m. I didn't install the included temp sensor, as it says it's optional and I just wanted to get it working generally before deciding whether I want that or not.
But it just doesn't seem to be working right. Closing the relay doesn't always cause the Navien to react (which I suppose is expected, because apparently there's internal logic to prevent a cycle within X minutes of a previous cycle or hot water being used at all)...but on the occasions where it does react, here's what happens...
1. I hear the Navien spring into action
2. The recirc and burner symbols light up
3. I feel water just barely starting to move thru the return line
4. 2-3 second later, everything stops and the Navien returns to inactive
That's it. Nothing else happens. And the return line is still cold.
I read multiple posts talking about the Energy Saver mode controlled by the #2 dip on the hot button board. Mine has the solder points, but no switches. So I soldered #2, re-installed it. No change in behavior at all. And I'm not even convinced that was the issue, anyway. Because Energy Saver mode is supposed to restrict the cycle to 30 seconds, not 3.
This can't be correct, right? What is causing it to seemingly start a recirc cycle and then immediately shut down?
The Navien is working perfectly normal otherwise. Calling for hot water from any faucet continues to work fine.
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