Navien NPE 240A

[Wes Anderson]

Six months or so ago I had an NPE 240A installed. I was set up with external recirc line (I think) but don't feel I'm getting much benefit. I'm waiting 1 min 30 seconds or longer for hot water to get to end of the line (kitchen sink ~60 feet from tankless). This is no big deal and I know it is a typical 'con' of the tankless. I just want to get a double check on how we have it set up.

I know the plumber told me I had external recirculation, but not sure if I have an external pump or not - I think its just using the internal pump. The 1-3 DIP switches are in "Off/On/Off" position which I think confirms this per the manual. I have not yet confirmed if the valve is in the "EXT" position and I will do this when I return home in a few days.

See the picture below of the front of the system, which may help someone see how we have it set up.

I think my main question is that if I am indeed operating with the internal pump, are you much surprised that there's such a wait??

Anybody get much benefit from the "Intelligent Preheating" feature? I could potentially add that - plumber didn't think it would help much.

 

[FDNY/RETIRED]

Check this out even though he is showing for internal pump. Just follow the reverse procedures when checking. If you think you have external pump setup

 

[Sponsor]

 

[Wes Anderson]

Well I am home today and I checked this valve that has "EXT" and "INT" positions and sure enough, mine was set to "INT".

So if plumber's DIP switches are correct (Off, On, Off) then he got this wrong. Alternatively, if he got this right, his DIP switches are wrong...but I would think I would know if I had an external pump installed - nobody ever told me that.

How might I tell if I am running on internal or external recirculation?

 

[Fitter30]

Here's the dip switch settings cycle power after changing

 

[Wes Anderson]

Welp that was definitely it. The valve was on "INT" not "EXT". What was 1 min 30 seconds in places is now 10-15 seconds. Incredible.

In summary: Apparently I was set up with external recirculation using the internal pump. DIP switches were correct. However, the 2-way valve inside the machine was not turned to "EXT" so there was no way for the machine to recirculate externally.

 

[Breplum]

Good for you figuring it out!
A tip. When, in a year or whenever appropriate for descaling based on water quality, do rotate the INT/EXT temporarily to INT while descaling fluid is pumping. Then back to normal EXT when done.
I have to say: That valve has the worst concept for eyeball check. They should have a reminder decal or some other indicator to tell which way it is set!