Navien NPE240A- Navilink,Navilink App, Recirculation settings And Parameters

Users who are viewing this thread

Dradam

Member
Messages
51
Reaction score
2
Points
8
Location
Washington, DC
Navien NPE 240A— Navilink recirculation—some customer insights.



I have had The Navien NPE240A for about two years now and the unit has worked flawlessly, but it has taken me a while to get my recirculation settings working and recirculation parameters dialed in.

I thought I would share here some of the things I have learned in the hopes it may help others as they consider this system. I welcome any comments or corrections.

I was interested in this system because it seemed to offer the most control through their Navilink app, and the ability to control scheduled recirculation.

I have an older home so a dedicate recirculation line was not an option for me. I am currently set up to recirculate warm water through to my farthest fixture using the cold-water line as a return. I recently upgraded from A Grundfos bypass valve to Naviens’ “Navicirc” bypass valve which I believe has a better flow and a higher closing temp.


Some things to know before your buy:

I chose the NPE240A because of its internal tank to provides a small reservoir of instantly hot water. During a recirculation cycle I don’t think this makes much of a difference because the water lines in my home are effectively the water tank. Off recirculation, on demand, this may help.

In new construction I believe that a dedicated recirculation line to the farthest fixture is the way to go. Using the cold-water lines as the return limits how high the initial temperature can be at the farthest fixture. The Navicirc bypass closes at 95 degrees. This is an effort to not make the cold-water lines too hot. With a dedicated recirculation line, I believe the temperature can be as you set it. I do not at all mind having warmer water in the cold lines during recirculation. While I guess some of that warm water could be going down the toilet, in my household the recirculation times are mainly shower times.

Navien makes it clear that they will only provide warranty support to units installed by their licensed contractors. While I have tackled many DIY projects this combination of plumbing, gas and venting was clearly best left to a qualified installer. Be careful that your installer has experience with these units. I live outside D.C. and used “Tankless Concepts”. Tankless heaters are all they do. They did a great job for me.

Navien does not make clear the difference between scheduled recirculation and their “Hot Button”. The hot button ( in the navilink app)does a short recirculation cycle when you hit it bringing hot water to the farthest fixture.(there is also an option for a hard wired hot button) The Navilink app is software based for both IOS and Android. It communicates with their “Navilink” device. The app and the Navilink communicate either CAT5 wired or wirelessly to your router through you homes WIFI setup. The Navilink then controls your NPE. You can set a schedule on the app to tell your unit when to recirculate water through your lines. The scheduler controls the recirculation only. There is a separate switch which can shut down the unit if needed.

The hot button is different. Even though it uses the same app. The hot button requires installation of a circuit board into the unit. When the hot button is activated scheduling is disabled. You can not have both. This does not make a lot of sense to me. Ideally, I would like to have a schedule in the morning and then be able to use a hot button later in the day if needed off schedule. I see no reason that the app could not incorporate a software based hot button and I have suggested this to Navien.

There is however a work around… If you disable the scheduler in the app a recirculation cycle will begin. But you must remember to turn it back on again or your device will continue to recirculate.


My biggest problem over most of my first two years of use was getting the scheduler to work and it came down to a simple issue. There is a button on the app for the weekly scheduler that says “enable” I would set the schedule and hit the enable button. What I recently learned is that the schedule is on when the button says “enable” and off when it says “disable”. Is should read “enabled/disabled” This is a Korean app developer language issue. I have notified Navien of this as well and I see that it has confused many others as well.

My second biggest issue has been optimizing recirculation parameters. For recirculation Navien is not clear as to the use of parameters. There is always an interval between when water is called for and the start of the burner. During this delay gases are blown out of the exhaust and cold-water flows through the burner unheated leading later to a cold-water sandwich. I hoped that tweaking the parameters might mitigate this effect.

Follow me here….and I think this is only relevant for those who use the cold system to recirculate. I can’t stop a cold-water flow at initial start up of the burners, but I hoped that by tweaking the parameters I might regulate the temperature of my pipes and soften the blow. Effectively using the water and heat in the piping as a buffer against the initial cold-water startup infusion.

Three parameters are relevant here:

P12: Pump Cycle Interval time- The amount of time the pump will run when a recirculation is called for. This was originally set to five minutes by my installer because that is how long it took warm water to get to my farthest fixture. At this setting I was getting a cold-water sandwich. I increased this to six minutes and saw a marked improvement.

Why? My theory: five minutes got water to the farthest fixture but did not fill up all the returning cold line to the NPE. My shower has a temperature regulator. It draws on both the hot and cold lines to maintain its set temp. If there is already warm water in the cold system, it will pull hot less quickly from the hot system. My thinking is that the cold-water rush at startup will have more time to warm up in the pipes before it hits me. I have only now experienced “warm water sandwiches” but not cold.

P14: Return line sampling.: I reduced this from default of 30 minutes to 15. My thinking that with more frequent sampling it would pull more warm water into the pipes and keep my ‘Pipe Buffer” hotter. I was concerned that with longer sampling intervals the water in the pipes would cool down more.

P 15: Recirculation differential temperature: I interpret this as the difference between set temp and the return water temp that will turn initiate a recirculation cycle. The default is 9 F. I have set mine to 5F. I am not sure this can make any difference in a cold-water recirculation line set up because the Navicirc valve closes at 95 degrees F. it may be a more relevant adjustment for those with a dedicated hot water line.

P16: This is only relevant if you are using the hot button and allows on to determine the recirculation

time needed to your farthest fixture.

For the Navilink and recirculation to work:

P01 must be set to your type of device

P17 must be on for thermal bypass

P18 must be on to allow communication with the Navilink.

I have not adjusted any other parameters as they do not affect recirculation to my knowledge.

In the unit dip switches and valves must also be set correctly if you are using external recirculation. This is listed in their most recent technical bulletins and should be set up by your installer.

Final thoughts:

It has been my impression That the Navicirc works better than the Grundfos valve.

Endless hot water has been fantastic.

I added piping to an outdoor hose bib that I can be switched to hot water. I use it to refill my hot tub after cleaning and to fill up my pool at the beginning of a season. Extravagant yes, but the water would be heated regardless and this way it is almost instantaneous.

I can’t say enough good things about the “Tankless Concepts” the company who did my install. Technical bulletins, the app and other things have changed even since my install and they have been amazingly responsive to my questions.


Navien has done some recent app updates;

I believe they have fixed the inability to register with IOS 13, but if not, you can register with a device using an older IOS if you have one.

There has been an issue with schedules not changing automatically over daylight saving time. This may have been fixed but I won’t know until clocks change again.

I have asked them to create an app based hot button that does not preclude a schedule as well.

I have asked them to correctly label the enable/ disable buttons.

If my thinking is flawed here or if anyone has any helpful suggestions please let me know. I hope this has been helpful.
 

Eric The Red

New Member
Messages
1
Reaction score
0
Points
1
Location
Texas
I just got off the phone with a "Senior" support specialist. I too have the NPE-240A, and this is what was explained to me.
1. When its just the water heater there is a 30 minute/9 degree re-circulation default set up
2. Connecting a Hot Button or a Navilink controller to the tankless water heater disables this default because it is assumed that when you hook a Hot Button up you will only want it recirculating when you engage it to do so manually, and when you hook up a NaviLink that you will want to have schedules set up. If you have a hot button and a Navilink hooked up you get the option of one or the other in the app. not both.
3. This means that when the schedule is disabled it will NOT heat/recirculate.
4. It means that when outside of the schedule parameters it will NOT heat/recirculate.

I set my schedule for 7AM when I wake up to 10PM when Everyone would no longer take showers. From what I was told this means it will not run/recirculate overnight from 10:01PM to 6:59AM because of this schedule.

5. So having found this out, it would seem that the only way to engage a "hot button workaround" would be to enable the schedule...have it figure out/sense the reservoir tank is cold and begin heating the reservoir tank and therefore initiating a re-circulation. There is not a workaround if you have the schedule enabled; disabling it does not initiate a re-circulation.
 

Dradam

Member
Messages
51
Reaction score
2
Points
8
Location
Washington, DC
If the hot button is not engaged, or a schedule is not specified and enabled in the app then the water heater simply will not re-circulate. Quote

Have you tried creating a schedule but then disabling the schedule? With a specified schedule if I then disable the schedule my unit will run 24/7 recirc/heat.

Is your hot button circuit board still installed? Mine is not. It can be easily removed.

5. So having found this out, it would seem that the only way to engage a "hot button workaround" would be to enable the schedule...have it figure out/sense the reservoir tank is cold and begin heating the reservoir tank and therefore initiating a re-circulation. There is not a workaround if you have the schedule enabled; disabling it does not initiate a re-circulation.[/QUOTE]

With Navilink installed and communicating (no hot button board installed) and my scheduled program "disabled" my unit recirculates and heats 24/7 as though it were a regular heater as you have shown above 30 min /9 degrees . When my programmed schedule is enabled(working) and I want to take a shower "off" schedule disabling the programmed schedule will initiate unit recirculation and heat if the temp has dropped- hence the workaround. This does indeeed work for me. You must then hit enable again to go back to your schedule or the 30 min 9 degree recirculation will apply 24/7. If this is not your experience perhaps the firmware has changed since my install about 3 years ago. Or perhaps if your hot button circuit board is installed it may have an effect. Be sure your Parameters and dip switches are set correctly.

To test this ----while the schedule is enabled (and no hot button installed), but you are off schedule go to the unit and then hit disable on the app. If yours works like mine you will see the symbol for recirculation start within moments.

Obviously the best option would be for Navien to create an app based Hot Button (no additional circuit board) which can be used in conjunction with the scheduler. Despite multiple posts and e-mails they have not done it. That said adding a "D" to the words enable and disabled should be an easy software fix. I ditched and removed the hot button circuit board early on because it did not allow the app to set a schedule. It was one or the other as you have noted. I never tested the "workaround" with the hot button board installed.

I set my schedule for 7AM when I wake up to 10PM when Everyone would no longer take showers. From what I was told this means it will not run/recirculate overnight from 10:01PM to 6:59AM because of this schedule Quote.

What you say here is correct-- I hope you know that you can set multiple schedules in one day- such as showers from 7-10 am and 7-pm to 10pm. The unit will not heat or recirculate between schedules(unless you disable the schedule)

Best wishes.
 

ASB

New Member
Messages
1
Reaction score
0
Points
1
Location
CA
If the hot button is not engaged, or a schedule is not specified and enabled in the app then the water heater simply will not re-circulate. Quote

Have you tried creating a schedule but then disabling the schedule? With a specified schedule if I then disable the schedule my unit will run 24/7 recirc/heat.

Is your hot button circuit board still installed? Mine is not. It can be easily removed.

5. So having found this out, it would seem that the only way to engage a "hot button workaround" would be to enable the schedule...have it figure out/sense the reservoir tank is cold and begin heating the reservoir tank and therefore initiating a re-circulation. There is not a workaround if you have the schedule enabled; disabling it does not initiate a re-circulation.

With Navilink installed and communicating (no hot button board installed) and my scheduled program "disabled" my unit recirculates and heats 24/7 as though it were a regular heater as you have shown above 30 min /9 degrees . When my programmed schedule is enabled(working) and I want to take a shower "off" schedule disabling the programmed schedule will initiate unit recirculation and heat if the temp has dropped- hence the workaround. This does indeeed work for me. You must then hit enable again to go back to your schedule or the 30 min 9 degree recirculation will apply 24/7. If this is not your experience perhaps the firmware has changed since my install about 3 years ago. Or perhaps if your hot button circuit board is installed it may have an effect. Be sure your Parameters and dip switches are set correctly.

To test this ----while the schedule is enabled (and no hot button installed), but you are off schedule go to the unit and then hit disable on the app. If yours works like mine you will see the symbol for recirculation start within moments.

Obviously the best option would be for Navien to create an app based Hot Button (no additional circuit board) which can be used in conjunction with the scheduler. Despite multiple posts and e-mails they have not done it. That said adding a "D" to the words enable and disabled should be an easy software fix. I ditched and removed the hot button circuit board early on because it did not allow the app to set a schedule. It was one or the other as you have noted. I never tested the "workaround" with the hot button board installed.

I set my schedule for 7AM when I wake up to 10PM when Everyone would no longer take showers. From what I was told this means it will not run/recirculate overnight from 10:01PM to 6:59AM because of this schedule Quote.

What you say here is correct-- I hope you know that you can set multiple schedules in one day- such as showers from 7-10 am and 7-pm to 10pm. The unit will not heat or recirculate between schedules(unless you disable the schedule)

Best wishes.[/QUOTE]

Hi. Thank you for posting all this info. I also have a Navien NPE 240A that is approx 4 years old in a new home I purchased. The home has a hot water recirculation line. I've contacted Navien support and also had the highest rated tankless company in the area service and check the unit, but can't seem to get a consistent answer regarding the correct/best recirc settings for this unit. Hoping your experience can help me get this right.

I currently have dip switches 1 and 2 "on" (up) - supposedly to take advantage of the "intelligent pre-heating" and the valve set to 6 o'clock (external). As far as I know, all parameters are set to default. My experience is similar to the issue in your original post in that after the water sits in the lines without demand for a couple hours or so, it takes nearly 2 minutes to get to warm and then another 30 secs or so to get to hot. Not happy. Once a fixture is run and the loop is hot, it's hot at any fixture. I'm used to my other homes that have had an external pump and sidearm tank with a ready supply of hot so this has been a major fail.

Your post leads me to believe my settings for dip switches and parameters are outdated/wrong. Based on above, what do you recommend based on what you've learned? Thanks very much.
 

spacecowboy

New Member
Messages
1
Reaction score
0
Points
1
Location
wild west
Having just run my own recirc lines and installing an NPE240A I can tell you that you don’t want intelligent preheat.

The intelligent preheat time watches when heat is called for for about a week and only recircs at that time. If your schedule is not the exact same daily, the system will alway be ‘learning’ and never recirc.

You will be much happier flipping dip switch 1 off and leaving 2 on and keeping the 2 way valve closed (ext at 6 o clock) to put it in external recirc mode. It will sample the line every 30 minutes and heat the loop if its 9 degrees or more colder than the set temp. If you’re loop is set up right, you’ll have near instant hot water at the expense of burning gas.

If you want the best of both worlds, get either the navilink or NR20DU remote controller so you can schedule times when you want it to recirc or not.

I’m still running the numbers to figure out gas usage that recirc for my loop eats before deciding on nothing vs insulate the lines vs controller vs both.

SC
 

Dradam

Member
Messages
51
Reaction score
2
Points
8
Location
Washington, DC
I agree with Spacecowboy-- The information I have refers to external recirculation with cold water line return, but I expect the settings would be the same with a dedicated return line. dip one off, dip 2 on, everything else off (down is off)

I can send a copy of the Bulletin -- but I can't seem to uplad it here I anyone messages me.
 

Dradam

Member
Messages
51
Reaction score
2
Points
8
Location
Washington, DC
Here is the parameter list
 

Attachments

  • Navien npe240a parameter list.jpg
    Navien npe240a parameter list.jpg
    109.3 KB · Views: 1,430

Michael Reily

New Member
Messages
2
Reaction score
0
Points
1
Location
Grass Lake, Michigan
Hello all. I have had my professionally installed NPE-240A for about 8 months now and like it, but do experience longer times to get hot water to all the taps. Today I opened the front panel and saw that all the dip switches were set to off. Am I correct in assuming this means that the internal loop and buffer tank only heat up when there is there is demand for hot water (i.e. a faucet is open) and no recirculation is occuring? From what I have read, I need to set SW1 to on to enable the internal loop recirculation. I expect that would have some positive effect on the time to deliver hot water, even if it is small. The unit is in on one side of our basement and the kitchen is on the far side of the house on the first floor. Eventually, I want to run a return line from the kitchen area back to the hot water heater and that should significantly reduce the delivery time, since all the faucets feed off the line that leads to the kitchen.
 

Omer

New Member
Messages
1
Reaction score
0
Points
1
Location
Tucson Az
All,

Thank you for all the information...It's all very helpful.
I have an NPE-240A that's about a year and a half old and am looking to get the recirc working right.
My house has separate lines running from a hub close to the heater, so I'm looking at putting NaviCirc valves in 3 different places.
Like Spacecowboy pointed out, the learning cycle pretty much sucked.
I'm not concerned with running a schedule and just want to be able to recirculate the water when ever it's needed.
After reading all your posts and the manuals from Navien, it looks like I have to install the Navi link AND the HotButton kit in order to be able to use the app to to recirculate the water on demand. Is that correct?
I'm trying to avoid running wires through the house to get the buttons more conveniently located that's why I want to be able to do it wirelessly.
 

rgrichar

New Member
Messages
1
Reaction score
0
Points
1
Location
Toronto, Canada
Navien NPE 240A— Navilink recirculation—some customer insights.




Just had a new NPE-240A installed last week, replacing a NR-240A we'd had for 10 years. Seems many people had problems with the NR-240A and many didn't. Unfortunately ours was trouble off/on from year 2 to the end. It would ramp up/down repeatedly, inconsistent water temps, once/twice a year need a power cycle to work, but would never misbehave on demand, facilitating a solution.

Such with Navien as spec was extremely limited and utilizing same size/spacing on unit and venting was an advantage. My friend/installer also assured my newer units were better.

I got mine installed with NaviLink and HotButton kit. I wanted the NaviLink functionality, and thought may as well have HotButton as well to experiment with. The NaviLink user guide notes NaviLink /HotButton functionality thru the app and also daily scheduling.

But now I find out that the Hot Button precludes setting any schedule and prevents app from providing that option. I had uncovered this myself and confirmed with Navien, but this forum is the only place I've seen it spelled out clearly. Manuals do state Hot Button overrides schedules but that's a little different from "makes setting schedule impossible". The NaviLink brochure notes NaviLink can "activate recirculation on NPE-A with HotButton" and Schedule recirculation by hour or by day". I had my installer check with Navien before hand and they confirmed you can have a schedule with HotButton - only to change tune when questioned again today.

So besides ranting, to contribute something positive my thoughts are:

The previous NR240A made a considerable cold water sandwich if outside of recirculation period and turning hot water on / off / on. Even though cold out now, the NPE seems to do a much better job in same situation - it's more like a quick warm water sandwich. Hand I fully appreciated this, I might have skipped the recirc feature entirely and saved some $$

I have an external recirculation loop in my basement that covers 7/8 to 1/2 of the hot water path to all my fixtures (2 storey house). Had previously used it with the NR240A but was excessive on gas usage vs just using internal recirculation and buffer tank. I previously scheduled 12 hours a day for recirculation.

Now I'm looking at removing hot button and just using a schedule. Will verify gas usage (from NaviLink app) to compare internal and external loops. Maybe the new NPE is more efficient than the NR

It's too bad HotButton is limited to 5 min runtime max. While I could possibly have extended a wire to the kitchen for a actual button, I was interested in wiring the hot button contacts to a Z-Wave relay, connecting relay device wireless to Z-Wave Hub and then Z-wave hub to Alexa. I have Alexa pretty much everywhere so "Alexa Turn On Hot Water" should have worked well.

Would have been at least $100 experiment for Z-wave components. Commanding Alexa while making bed prior to bathroom would have been ok, but having recirculation end a 5 minutes, seems kind of pointless.... 20-30 minutes would have been more like it.

I'll monitor this thread - maybe others will post ideas to make the HotButton functionality more useful - or notice of improvements from Navien
 

Bannerman

Well-Known Member
Messages
4,795
Reaction score
768
Points
113
Location
Ontario, Canada
Maybe the new NPE is more efficient than the NR
Efficiency factor specifications for NPE-240A = 96% vs 95% for NR-240A. With only 1% difference, you will likely not realize much if any noticeable energy savings in running 12-hour circulation with the new unit vs the model it replaces.

Perhaps an acceptable option will be to utilize the Intelligent Pre-Heating feature as that will recognize repeated usage patterns and will run circulation based on that schedule.

Although the HotButton feature will only activate circulation for max 5-minutes, water will remain hot in an insulated supply line for some time. Even after the 5-minutes has elapsed, the water may remain acceptably warm within the supply line for the additional 15+ minutes you mention.

For HotButton to reactivate for a 2nd 5-minute timer, the timer would first need to elapse as a further button press will be ignored until an active timer has timed-out.

To activate the HotButton option with your Alexa device, the smart switch listed below may be useful. Although frequently used for controlling an electric garage door operator using WIFI, the switch offers a momentary contact relay so I anticipate it could be wired as a Hot Button. Perhaps Alexa or the switch app may be programmed to repeat pump activation automatically 6, 7 or 10 -minutes after it has activated the pump initially.

https://www.amazon.ca/dp/B0752P57ZG/ref=as_li_ss_tl?keywords=ewelink+module&language=en_US&ie=UTF8&sr=8-1&linkCode=gs2&linkId=7b93392fcd98392bd94c34a45a30dfb2&tag=twhomeshow07-20
 
Last edited:

Sonny goldstone

New Member
Messages
23
Reaction score
0
Points
1
Location
Philadelphia
Hi there...just curious since I was considering a Navien 240A.

On my Noritz, every time the heater is used the fan activates and it’s not super loud but it is loud enough that I can hear it spin up from the room next to it.

Does the Navien also turn its fan on after each use and if so would you say it’s noticeably loud?
 

Trimeistergeek

New Member
Messages
2
Reaction score
0
Points
1
Location
Michigan
I just had an NPE240A2 professionally installed last week. The A2 is the upgrade that started shipping in March 2021. It does not appear to be that much different. My unit is a replacement for an existing electric tank recirc loop system. The installers insisted they did not need to pipe the recycle return...they wanted to cap it off. Finally I got them to call the Navien support line to set them straight.

They installed the NaviLink, but left without enabling it (I am sure they had no idea of how to get to the installer menu and enable it.) The A2 manual explained the steps to enable...which is different from the old NPE-A models. Thanks to the conversation here, I was able to understand that "Enable" in the app means the schedule is enabled. The NaviLink manual left by the installers and the manual on-line do not give any details on how to program the schedule. I thought that was odd.

Currently I have the recycle loop active for a few hours in the morning and a few hours at dinner. If I want the recycle to run outside of those times, I just hit the "Enable" button on the app, which illogically disables the schedule and returns to my default which is 24/7 recycle on.

I think it is odd that they choose to use the orange color (from their logo) to indicate "active" status in the app. Green is the universal color for active and orange/yellow usually means "caution." The power on/off button on the app is orange when "active". It makes me think there is something wrong, but that appears to be their color for "active." Similarly, the "Enable" button is orange. "Disable" however is grey. You would think after all of the complaints and confusion they would update this behavior.

Naven also needs to do a better job training installers or being more selective about who their installers are. I felt like I had bought a Lexus but was getting used-car customer service.
 

Dradam

Member
Messages
51
Reaction score
2
Points
8
Location
Washington, DC
Glad this thread was able to help you-- The app could really use clarification and a reboot. The enable/disable work around for a hot button really speaks to the fact that they could just make an app based digital hot button alone-- with a timer better yet to resume the normal schedule.

One note in case you have not seen it yet.. The app does not adjust for daylight savings time. The fix is that you can at least change the time in the app settings menu under change Navilink information.

If you have the chance can you post the differences in the npe240a2 vs the a.

Best.
 
Q

Quark

Guest
When the hot button is activated scheduling is disabled. You can not have both. This does not make a lot of sense to me. Ideally, I would like to have a schedule in the morning and then be able to use a hot button later in the day if needed off schedule. I see no reason that the app could not incorporate a software based hot button and I have suggested this to Navien.
Greetings from Virginia . . . we have a 240A with external recirculation and I am considering buying NaviLink with the optional HotButton. We would like to schedule the circulation pump (CP) to NOT activate between 10 PM and 6 AM. Between 6 AM and 10 PM we would like to use either a physical button and/or software-based buttons on our iPhones and iPad to activate the CP. Navien Tech Support tells me that we can activate the HotButton using our iPhones and iPad and that, yes, using the HotButton will disable scheduling. However, Tech Support also tells me that re-enabling the schedule(s) using the NaviLink app is easy to do.
Given the highly critical reviews of the NaviLink app on the Apple iOS App Store, I am reluctant to buy until I can verify that 1) re-enabling schedules using the NaviLink app is easy to do and 2) we can use the NaviLink app to activate the CP on-demand (in other words, the app does, indeed, have a software-based button). Thanks in advance for any advice.
 

JerryD

New Member
Messages
1
Reaction score
0
Points
1
Location
San Diego, CA
Navien NPE 240A— Navilink recirculation—some customer insights.



I have had The Navien NPE240A for about two years now and the unit has worked flawlessly, but it has taken me a while to get my recirculation settings working and recirculation parameters dialed in.

I thought I would share here some of the things I have learned in the hopes it may help others as they consider this system. I welcome any comments or corrections.

I was interested in this system because it seemed to offer the most control through their Navilink app, and the ability to control scheduled recirculation.

I have an older home so a dedicate recirculation line was not an option for me. I am currently set up to recirculate warm water through to my farthest fixture using the cold-water line as a return. I recently upgraded from A Grundfos bypass valve to Naviens’ “Navicirc” bypass valve which I believe has a better flow and a higher closing temp.


Some things to know before your buy:

I chose the NPE240A because of its internal tank to provides a small reservoir of instantly hot water. During a recirculation cycle I don’t think this makes much of a difference because the water lines in my home are effectively the water tank. Off recirculation, on demand, this may help.

In new construction I believe that a dedicated recirculation line to the farthest fixture is the way to go. Using the cold-water lines as the return limits how high the initial temperature can be at the farthest fixture. The Navicirc bypass closes at 95 degrees. This is an effort to not make the cold-water lines too hot. With a dedicated recirculation line, I believe the temperature can be as you set it. I do not at all mind having warmer water in the cold lines during recirculation. While I guess some of that warm water could be going down the toilet, in my household the recirculation times are mainly shower times.

Navien makes it clear that they will only provide warranty support to units installed by their licensed contractors. While I have tackled many DIY projects this combination of plumbing, gas and venting was clearly best left to a qualified installer. Be careful that your installer has experience with these units. I live outside D.C. and used “Tankless Concepts”. Tankless heaters are all they do. They did a great job for me.

Navien does not make clear the difference between scheduled recirculation and their “Hot Button”. The hot button ( in the navilink app)does a short recirculation cycle when you hit it bringing hot water to the farthest fixture.(there is also an option for a hard wired hot button) The Navilink app is software based for both IOS and Android. It communicates with their “Navilink” device. The app and the Navilink communicate either CAT5 wired or wirelessly to your router through you homes WIFI setup. The Navilink then controls your NPE. You can set a schedule on the app to tell your unit when to recirculate water through your lines. The scheduler controls the recirculation only. There is a separate switch which can shut down the unit if needed.

The hot button is different. Even though it uses the same app. The hot button requires installation of a circuit board into the unit. When the hot button is activated scheduling is disabled. You can not have both. This does not make a lot of sense to me. Ideally, I would like to have a schedule in the morning and then be able to use a hot button later in the day if needed off schedule. I see no reason that the app could not incorporate a software based hot button and I have suggested this to Navien.

There is however a work around… If you disable the scheduler in the app a recirculation cycle will begin. But you must remember to turn it back on again or your device will continue to recirculate.


My biggest problem over most of my first two years of use was getting the scheduler to work and it came down to a simple issue. There is a button on the app for the weekly scheduler that says “enable” I would set the schedule and hit the enable button. What I recently learned is that the schedule is on when the button says “enable” and off when it says “disable”. Is should read “enabled/disabled” This is a Korean app developer language issue. I have notified Navien of this as well and I see that it has confused many others as well.

My second biggest issue has been optimizing recirculation parameters. For recirculation Navien is not clear as to the use of parameters. There is always an interval between when water is called for and the start of the burner. During this delay gases are blown out of the exhaust and cold-water flows through the burner unheated leading later to a cold-water sandwich. I hoped that tweaking the parameters might mitigate this effect.

Follow me here….and I think this is only relevant for those who use the cold system to recirculate. I can’t stop a cold-water flow at initial start up of the burners, but I hoped that by tweaking the parameters I might regulate the temperature of my pipes and soften the blow. Effectively using the water and heat in the piping as a buffer against the initial cold-water startup infusion.

Three parameters are relevant here:

P12: Pump Cycle Interval time- The amount of time the pump will run when a recirculation is called for. This was originally set to five minutes by my installer because that is how long it took warm water to get to my farthest fixture. At this setting I was getting a cold-water sandwich. I increased this to six minutes and saw a marked improvement.

Why? My theory: five minutes got water to the farthest fixture but did not fill up all the returning cold line to the NPE. My shower has a temperature regulator. It draws on both the hot and cold lines to maintain its set temp. If there is already warm water in the cold system, it will pull hot less quickly from the hot system. My thinking is that the cold-water rush at startup will have more time to warm up in the pipes before it hits me. I have only now experienced “warm water sandwiches” but not cold.

P14: Return line sampling.: I reduced this from default of 30 minutes to 15. My thinking that with more frequent sampling it would pull more warm water into the pipes and keep my ‘Pipe Buffer” hotter. I was concerned that with longer sampling intervals the water in the pipes would cool down more.

P 15: Recirculation differential temperature: I interpret this as the difference between set temp and the return water temp that will turn initiate a recirculation cycle. The default is 9 F. I have set mine to 5F. I am not sure this can make any difference in a cold-water recirculation line set up because the Navicirc valve closes at 95 degrees F. it may be a more relevant adjustment for those with a dedicated hot water line.

P16: This is only relevant if you are using the hot button and allows on to determine the recirculation

time needed to your farthest fixture.

For the Navilink and recirculation to work:

P01 must be set to your type of device

P17 must be on for thermal bypass

P18 must be on to allow communication with the Navilink.

I have not adjusted any other parameters as they do not affect recirculation to my knowledge.

In the unit dip switches and valves must also be set correctly if you are using external recirculation. This is listed in their most recent technical bulletins and should be set up by your installer.

Final thoughts:

It has been my impression That the Navicirc works better than the Grundfos valve.

Endless hot water has been fantastic.

I added piping to an outdoor hose bib that I can be switched to hot water. I use it to refill my hot tub after cleaning and to fill up my pool at the beginning of a season. Extravagant yes, but the water would be heated regardless and this way it is almost instantaneous.

I can’t say enough good things about the “Tankless Concepts” the company who did my install. Technical bulletins, the app and other things have changed even since my install and they have been amazingly responsive to my questions.


Navien has done some recent app updates;

I believe they have fixed the inability to register with IOS 13, but if not, you can register with a device using an older IOS if you have one.

There has been an issue with schedules not changing automatically over daylight saving time. This may have been fixed but I won’t know until clocks change again.

I have asked them to create an app based hot button that does not preclude a schedule as well.

I have asked them to correctly label the enable/ disable buttons.

If my thinking is flawed here or if anyone has any helpful suggestions please let me know. I hope this has been helpful.
I thank you for this post! On 12/6/2022 I just installed a Navien 240 A and talked to tech support for Navien 3 times about the NaviLink not controlling the unit. Your observation about the “Enable/Disable” selection saved the day! Thank you for posting. I kept looking at the programming trying to figure out what was wrong. Navien even sent me a new NaviLink wireless controller which I installed with the same results. Then I searched and discovered your posting. On the App, the “Enable” button appears and is highlighted and now controls the times I have programmed for on/off. Thanks again Mate!
 

Dradam

Member
Messages
51
Reaction score
2
Points
8
Location
Washington, DC
I thank you for this post! On 12/6/2022 I just installed a Navien 240 A and talked to tech support for Navien 3 times about the NaviLink not controlling the unit. Your observation about the “Enable/Disable” selection saved the day! Thank you for posting. I kept looking at the programming trying to figure out what was wrong. Navien even sent me a new NaviLink wireless controller which I installed with the same results. Then I searched and discovered your posting. On the App, the “Enable” button appears and is highlighted and now controls the times I have programmed for on/off. Thanks again Mate!
Glad it helped !! I wish someine at Navien would read this and have the app updated. !!
 

TJanak

Member
Messages
240
Reaction score
8
Points
18
Location
South TX
I don't know the best place to post this, but i happened to be fiddling around in the NaviLink app on Feb. 1 and it asked to update. The update is not perfect, but seems to be much more user friendly interface. Still appears to have the same "Enable/Disable" terminology.

But, they appear to have fixed the daylight savings time issue! I was having to change my settings for on and off time when daylight savings time began and ended, but now the app lets you use your phone GPS to set your location, and it appears to now be correct with daylight savings time.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks