Navien NPE-240A and HotButton - DIP switches and parameters

[Quark]

Re: Navien NPE-240A, Internal Pump Only, External Recirculation and DIY install of HotButton (PZZZ-00046). The HotButton Installation Manual does not mention DIP switch settings. It specifies one parameter setting: P.12 (HotButton pump cycle time).

Q1: Should I leave DIP switches 1, 2 and 3 set to OFF ON OFF, respectively? These are the correct settings for the Internal Pump Only, Eternal Recirculation.

Q2: Annoyingly, the HotButton Installation manual does not match the NPE-240A Installation and Operations manual (or the actual P.12 parameter in our 240A) with respect to the naming and description of P.12. The former calls P.12 the “HotButton pump cycle time” while the ladder manual calls P.12 the “Preheat Pump Output Time”. Furthermore, the range and default values are vastly different. I suspect that the Hotbutton Installation manual pre-dates the NPE-240A manual. So, which parameters need to be set in a 240A and what are the recommended values?

For liability reasons, Navien Tech Support could not / would not advise me because I am the homeowner. Pay a licensed contractor for this information? Really? I would appreciate any advice. No liability concerns here!

 

[Dcortwilson]

Re: Navien NPE-240A, Internal Pump Only, External Recirculation and DIY install of HotButton (PZZZ-00046). The HotButton Installation Manual does not mention DIP switch settings. It specifies one parameter setting: P.12 (HotButton pump cycle time).

Q1: Should I leave DIP switches 1, 2 and 3 set to OFF ON OFF, respectively? These are the correct settings for the Internal Pump Only, Eternal Recirculation.

Q2: Annoyingly, the HotButton Installation manual does not match the NPE-240A Installation and Operations manual (or the actual P.12 parameter in our 240A) with respect to the naming and description of P.12. The former calls P.12 the “HotButton pump cycle time” while the ladder manual calls P.12 the “Preheat Pump Output Time”. Furthermore, the range and default values are vastly different. I suspect that the Hotbutton Installation manual pre-dates the NPE-240A manual. So, which parameters need to be set in a 240A and what are the recommended values?

For liability reasons, Navien Tech Support could not / would not advise me because I am the homeowner. Pay a licensed contractor for this information? Really? I would appreciate any advice. No liability concerns here!

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I believe installing the hot button disables the recirculation cycle. Does your unit still cycle through recirculation with your hot button installed? If not, the external recirculation DIP switch setting must be ignored and you could leave 1-3 turned off or leave 1 on and 2-3 off to take advantage of internal recirculation. Also, from reading the manual, looks like the P.12 settings are dynamically changed when it senses a hot button has been installed; that would explain the discrepancy in parameter settings and manual terminology. There are others on this forum much more knowledgeable than I am; I'm surprised no one else has chimed in and hopefully my comment bumps your topic.