Navien-NPE A2 Dedicated Recirc line, Hot Button Setup

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J0hn

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Greetings

We just had our 19 year old Bradford White 80 gallon water heater replaced with a Navien-NPE A2 using the dedicated return line that was installed when the house was built in 2003. The installer wasn't too familiar with the A2 model which has the internal recirc pump but I had looked into before hand and we got the system up and running in 'hot button/manual' mode after making the appropriate changes. (set to external recirculation and the internal 2 way valve also set to external recirc, pointing down)

My question/problem is the recirc pump is not running very long and the 'in water temp' does not appear to be getting up where I expected it to be. A did a lot of googling and one suggestion was to go into the installer's menu and change the 'fixture distance' setting so the pump would run longer. I have played around with it a bit, and even setting the distance to 400', the pump will only run for about 3 minutes max and the 'in water temp' only gets up to around 108 degrees, but it is an improvement over what it was doing. There is also a dip switch on the 'hot button controller module' that I changed to be on to disable the 'energy saver function'

Any ideas what I can do to get the pump to run longer to get the 'In Water Temp' up into the 120 degree range before shutting off?
 

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breplum

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Do you actually have a hot button installed? Then you can't set offset temp.
You should be able to set a higher incoming water temp. only if the hot button parameter is NOT used. Page 89
is where the operational parameters are laid out.
Your installer should have been more engaged, and Navien tech desk is reluctant to work with non-professionals.
In this case though, they should be able to help. The tech desk has vast knowledge on getting into the settings.
 

J0hn

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Yes, and thanks for the reply. Am I correct in thinking that if we have the water temp set at 130 degrees, that the recirc should run until the water in the line gets up into the 120's?

There is a hot button within 2' of the tankless. I actually called Navien yesterday and as you pointed out, they don't want to provide help to a homeowner. One of the problems with the 'installer' is they are actually a contractor hired by our Natural Gas Company (S Cal Gas) who is pushing these Tankless Water Heaters with a special rebate from them. (I can't complain on the price - $1,395 for the NPE-210A2 installed with removal of the old 80 gallon tank, including all permits and fees) But, I don't think they do too many units with a recirc as they had to special order the A2.

Regarding incoming hot water, when I disabled the 'energy saver function' (dipswitch #2 on the hot button module) it allowed me to change the 'Recirc Off Diff Temp from 9 degrees down to 5 degrees (this is supposed to shut the pump off when that temp is met) but apparently it's not working or I missed a setting somewhere. I will have to start looking through the manual,

Actually, we are going to use our home automation system (z-wave with Alexa voice commands) to control the recirc, just like we did when we had our conventional water heater.

 

breplum

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Sorry you are in a tough spot with the installers not being Navien competent. Such a good deal you got, though!
Do you have the manual on hand?
Going through each page again...or find a small contractor on the Navien site maybe avoid the NSS and look further down for an owner operator, like me.
 

J0hn

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I think I got it straightened out for now, thanks for your reply. I extended the distance to the furthest fixture to 500' and disabled the 'energy saver' feature and now when I manually activate the recirc pump, it takes about 3 minutes but the incoming water temp is getting up into the 120's. (Before with out conventional water heater, we would run the recirc pump for 4 minutes, but had no way of actually knowing what the water temp was, so we are used to a little delay). I was able to talk to a supervisor at the contractor and he is going to contact Navien and see if this is an acceptable way of doing it.
 

Jeff H Young

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cant do much for 1500 bucks less than 1/2 price on the job . Socialized hot water heating.
I had a partner and we contracted with so ca gas free water heaters for low income back in 92 a good year for us
 

J0hn

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cant do much for 1500 bucks less than 1/2 price on the job . Socialized hot water heating.
I had a partner and we contracted with so ca gas free water heaters for low income back in 92 a good year for us
Well in S Cal, there is a $1,000 rebate for anyone on the Navien Tankless since it has a UEF of .95 and the Gas Company is throwing this contractor another, special $900 rebate. I was going to install a tankless myself, but when I received an email about this deal from the gas company it was a no brainer. I paid the contractor and they handled all the rebate stuff, and this deal is open to anyone, no income limits or any hoops to jump through.

I have used the same contractor before - they came out to my house and replaced the single speed furnace blower motor with a variable speed, checked the duct works for leaks (fan test) as well as installed an EcoBee WiFi thermostat - all for free (in the name of saving energy, I guess)
 

Jeff H Young

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Well in S Cal, there is a $1,000 rebate for anyone on the Navien Tankless since it has a UEF of .95 and the Gas Company is throwing this contractor another, special $900 rebate. I was going to install a tankless myself, but when I received an email about this deal from the gas company it was a no brainer. I paid the contractor and they handled all the rebate stuff, and this deal is open to anyone, no income limits or any hoops to jump through.

I have used the same contractor before - they came out to my house and replaced the single speed furnace blower motor with a variable speed, checked the duct works for leaks (fan test) as well as installed an EcoBee WiFi thermostat - all for free (in the name of saving energy, I guess)
great thanks for info . I didnt think you were low income but there are a lot of programs for all. they (envirementalists) want to stop all gas burning in ca new homes I think are having areas that dont allow . we are short on electricity and pushing all electric cars and homes.
I met the Navian rep a few monthes ago he was telling me about it
 
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