Navien 240A (Controlling the Circulation Pump)

[Quark]

Our 240A uses an External Recirculation Line and, at this time, we have no accessories, e.g., NaviLink, Remote Controller (NR-20DU) or HotButtons. Attached screenshot shows the Parameter and DIP switch settings.

Is there a combination of settings and accessories that would allows us to control the Circulation Pump (CP) as follows?

- Between 10PM - 6AM, the CP will not activate unless we draw hot water or use a HotButton and
- Between 6AM - 10PM, the CP will activate if we draw hot water or use a HotButton or, if we are away from home during these hours, the CP will activate in accordance with the Parameter settings.

Basically, I am confused about when (or if) the CP will activate during the timeframes above if we use a NaviLink (with or without a HotButton) or a NR-20DU (with or without a HotButton).

 

[Breplum]

The pump normally also keeps the mini-tank up to temp., so it can come on at all hours.
In Intelligent mode, if you have consistent useage between 6AM-10PM, it will learn that pattern.
I've got no exp. with NaviLink and not taken the time to read up on it.
HotButton would minimize cycling, but I do believe the temp in mini tank maintence allows running at any hour for a quick burst.

 

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[Quark]

Thanks, this info is very helpful. One of our goals is to reduce or eliminate CP noise during sleeping hours because the 240A is in a small, dedicated utility closet not far from our MBR. We may have to shell out $$ to soundproof the utility closet if we want to get to zero CP noise.

 

[NaviNovice]

Hi Quark
I have been dealing with Navien for the past 4 months trying to do essentially what you are attempting. I purchased a NaviLink and to date have not been able to get the Navien Water Heater to follow the schedule. The recirculation pump will trigger every 20-30 min or when ever the temperature difference between in coming water is 9* different from set temperature. This operation consumes an enormous amount of Propane (in my case) very expensive.
14 calls to Navien Tech Support has had me change a check valve, make various parameter and DIP sw changes, and swap out a new Navilink. None of which worked.
The last suggestion is that the PCB and Front Panel are bad from power outage. (It has never worked from the get go)
I am waiting on a Certified Navien Tech to respond to me to make the swap. I only have 30 days left on my Labor warranty.
I am hoping this is the solution. But i don't have any faith it will fix it. I have a 240A also.
I am not a fan of the Hot button. as it would be a lot of work to have them installed at each fixture. If the NaviLink would work as advertised It would solve the problem.
I wish I had had a choice in the type and model water heater that was installed in my new construction house. I would have chosen Bosch.
For what its worth.

 

[Quark]

The recirculation pump will trigger every 20-30 min or when ever the temperature difference between in coming water is 9* different from set temperature.

I changed P.12 to 15 minutes and P.14 to 60 minutes and this did reduce cycling of circulation pump. However, as breplum points out, the pump has to baby sit the buffer tank and will activate as needed, when needed, at any time of day. I am holding off on NaviLink for now. Instead, I going to tweak the Parameters to reduce cycling and gas consumption without creating a cold water monster in the external recirculation line.

I am not a fan of the Hot button. as it would be a lot of work to have them installed at each fixture.

Initially, I backed away from the HotButton (HB) because I mistakenly assumed that a HB had to be co-located with the fixture or fixtures that experience unacceptable hot water delays and this meant running wires every which way. However, there is no need to run multiple wires if you are willing to sacrifice the convenience of having a HB close at hand, near every fixture (faucet or shower). Depending upon your floor plan and the location of your 240A, a single, centrally located HB might be the ticket. Punch the button and the pump and burner start the process of getting hot water to every fixture in your external recirculation line (assuming that you have an ERL).

Also, there are some innovative wireless ways (not supported by Navien) to beat the wiring hassle.
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I hope that PCB and Front Panel swap resolves your 240A issues. So far, we have had no problems with our 240A.