# **I just installed my RHEEM ECO-SENSE 180DVN3 tankless water heater



## 57_Hemi (Jul 28, 2010)

Just completed the install of my new RHEEM ECO-SENSE 180DVN3 tankless hot water heater (selling at the local Home Depots). Picked one up a few months back (early July) and finally got around to installing it this week.


*** MY PURCHASES ***

-Tankless unit (RHEEM ECO SENSE 180DVN3)
-Valve kit w/ pressure regulator 
-Direct 3"/5" Horizontal Vent kit (RTG20147)
-Gas pipes / nipples / pipe dope / gas rated 3/4' ball valve etc
-(2) 3/4" Flex lines (for H2o inlet / outlet) 
-A few copper pipes & fittings to re route my existing plumbing 
-(1) 2x4x8ft
-(1) 4ftx4ft 3/4" plywood
-#8 x1 1/2 wood screws
-Tapcons


Not too bad of an install except for the 2 road blocks I encountered on the way. 

-Removed old tank/ vent/ plumbing etc etc
-enlarged hole in block wall to fit new 5" diameter direct vent
-Tapconced 2 pcs of 2x4 onto basement wall then screwed 3/4" plywood onto supports for a nice new & clean mounting wall. 
-mounted unit & ran vent + wall plates (easy...direct out above unit)
-shut off main gas, cut existing & "commence" re route of new 3/4" gas lines to be installed.

***ROAD BLOCK #1***
-pre measured all gas pipes to get cut & threaded at local home depot. Arrived at H.D. only to be told thier pipe threader was broken. headed to the next **WHAT** same story... pipe threader out of commission. Called a 3rd H.D. and finally got them to cut and thread what I needed..... 3hours wasted.

-arrived home ran all gas lines
-re routed all plumbing
-turn gas ON check for leaks...... **EVERYTHING GOOD TO GO** 
-turn water ON check for leaks.... ""EVERYTHING GOOD TO GO""
-run wire & connect main remote control unit
-plug in unit to 120v receptacle..... "*GREAT!!!**


***ROAD BLOCK #2***
-Turn power onto unit.......NOTHING !!!!
WTF.... everything wired up, plumbed, gas fitted etc etc and the darn thing does not even turn on.
-double check receptacle...WORKING!!!!
-HMMMM must be faulty main control unit

**WELL** after staring at the thing for almost an hour trying to figure out what was going on I finally stumble upon what (to me) had to have been one of the most ridiculous fixes I have ever come to face. The remote control unit for the RHEEM is a simple 4' x 4' box (the size of some of your average t-stats out there) with a simple TEMP UP button TEMP DOWN button POWER on/off button & LED display. These units have a vinyl type board glued over the actual housing itself with the buttons lined up to the terminals under them. i decided to peel the entire control panel board off the unit only to find that....

*YES !!!!.....THE MANUFACTURER HAD GLUED THE CONTROL PANEL ONTO THE UNIT UPSIDE DOWN.....*

Therefore all 3 buttons on the LEFT were not coming into contact with the terminals beneath because they're actually located on the RIGHT SIDE of the unit. 

-Sooooo......I re applied the control board *IN THE CORRECT POSITION* onto unit. 
-plugged her back in and PRESTO !!!! shes working like a charm
(another 1 hour or so wasted) 

Well anyway.... shes working great now and I must say I do like the way it performs with exception to one problem i've heard about on this site. The time it takes for the hot H2o water to actually reach the tapset... OR "cold water sandwich" i hear its called.

I'll have to look into that problem by maybe insulating pipes to sort of "help out" for now.....(I donno) but all in all NOT BAD and I love the fact that I have a ton of space in my utility room now for future use. i guess the extra few bucks I might save in gas will be transferred over to paying for the extra water I use now after waiting an extra 5 seconds or so everytime I'm waiting for the HOT supply to come out.

Ah well..... :thumbsup:


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## acerunner (Dec 16, 2009)

well done!

cold water sandwich as I understand it isn't due to uninsulated water lines. Its because the water heater takes a second or so to trigger on. During that delay it lets through a bit of cold water. Whats already in the pipe is what was heated in the previous use, which has probably cooled a bit. You'll get warm-cold-hot, thus cold water sandwich. Insulating the pipes will make the warm water a bit warmer, but the cold water sandwich will still exist.

so that is my understanding. Someone correct me if I'm wrong.


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## 57_Hemi (Jul 28, 2010)

acerunner said:


> well done!
> 
> cold water sandwich as I understand it isn't due to uninsulated water lines. Its because the water heater takes a second or so to trigger on. During that delay it lets through a bit of cold water. Whats already in the pipe is what was heated in the previous use, which has probably cooled a bit. You'll get warm-cold-hot, thus cold water sandwich. Insulating the pipes will make the warm water a bit warmer, but the cold water sandwich will still exist.
> 
> so that is my understanding. Someone correct me if I'm wrong.


Thank You !!

As for the dreaded "cold water sandwich".....

I think you've pretty much explained it.... I just figure that if I insulate all pipes than for the short periods between hot h2o use at least it would stay warmer a bit longer. However, I know it wont cure the problem. Considering the fact that I am in the process of finishing my basement I'm going to re route all plumbing lines and get them to thier fixtures via shortest route. The present /existing plumbing in my basement is all over the place with way to many 90's and Tee's and runs that could have been shortened by large margins....this should help me out with the time it takes my hot h2o to get to the tapsets........we'll see.


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## Dr. Tankless (Nov 20, 2010)

A cold water sandwich is caused by the fact that most tankless water heaters work on staging, what this means is that when you first turn on a hot water tap, they go to a pre determined power or BTU output and after a couple of seconds they adjust either up or down, that is why you get a cold water surge or a very hot water surge. Insulating your water lines will have no effect on this staging. Tankless water heaters that have SELF MODULATING technology do not have this issue, you will always have to wait for the water in the lines that have cooled off, but no cold or hot water surge. Any tankless that claims to have this technology MUST have an inlet temperature sensor, and be FLOW ACTIVATED, not flow switch activated and it MUST have a Digital Temperature Setting, and state of the art electroni board, since Modulation is based on several factors. 1. Inlet Water temperature 2. Flow rate and 3. Software that can Instantly combine these 2 factors to produce only the power needed. If the tankless water heater you are considering does not have this technology, you will have inconsistent output temperature, dimming or flickering of your lights if it's electric and if gas same issues. There are many tankless water heaters available today, so do your homework and ask questions to ensure you make the right choice.


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## CyndyWarner (Nov 20, 2010)

Dr. Tankless said:


> A cold water sandwich is caused by the fact that most tankless water heaters work on staging, what this means is that when you first turn on a hot water tap, they go to a pre determined power or BTU output and after a couple of seconds they adjust either up or down, that is why you get a cold water surge or a very hot water surge. Insulating your water lines will have no effect on this staging. Tankless water heaters that have SELF MODULATING technology do not have this issue, you will always have to wait for the water in the lines that have cooled off, but no cold or hot water surge. Any tankless that claims to have this technology MUST have an inlet temperature sensor, and be FLOW ACTIVATED, not flow switch activated and it MUST have a Digital Temperature Setting, and state of the art electroni board, since Modulation is based on several factors. 1. Inlet Water temperature 2. Flow rate and 3. Software that can Instantly combine these 2 factors to produce only the power needed. If the tankless water heater you are considering does not have this technology, you will have inconsistent output temperature, dimming or flickering of your lights if it's electric and if gas same issues. There are many tankless water heaters available today, so do your homework and ask questions to ensure you make the right choice.


Dr. Tankless you seemed well versed on Tankless water heaters do you have any recommendations on a brand you recommend? Also are they worth the investment? The articles I have read are not favorable. Thanks


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## Dr. Tankless (Nov 20, 2010)

Are you looking for Electric or Gas?


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## Dr. Tankless (Nov 20, 2010)

Gas consider Takagi- www.takagi.com 
Electric - ecosmart- www.ecosmartus.com


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## CyndyWarner (Nov 20, 2010)

Dr. Tankless said:


> Gas consider Takagi- www.takagi.com
> Electric - ecosmart- www.ecosmartus.com


We are looking for gas but is one better? Plus I understand that electric will need a larger circuit? Thanks for your input.


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## md2lgyk (Jan 6, 2009)

I installed a Rheem Eco-Sense in the log house I built. A pretty simple job. I actually put it on an outside wall in my attic so the vent pipe is really short. But since they were coming to hook up my hybrid heat anyway, I paid the gas company to run the gas lines.


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## bugmenot (Jul 26, 2008)

57_Hemi said:


> Just completed the install of my new RHEEM ECO-SENSE 180DVN3 tankless hot water heater (selling at the local Home Depots). Picked one up a few months back (early July) and finally got around to installing it this week.
> 
> 
> *** MY PURCHASES ***
> ...


57 Hemi. Can you post some pictures of the exhaust, or explain what the set up for this unit. Also, 2 years in, how is the unit performing? Thanks!


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## cprao (Oct 26, 2009)

bugmenot said:


> 57 Hemi. Can you post some pictures of the exhaust, or explain what the set up for this unit. Also, 2 years in, how is the unit performing? Thanks!


My tank water heater is broken. I am also looking to install a tankless one.
I was advised locally Rheem product.

2 full showers and one faucet at the same time - ECO180 
3 full showers and one faucet at the same time - ECO200 or ECOH200.

I am planning to install outside (next to main gas line) to avoid vent.
This location is also good for two bathrooms. The other bathroom is away from two bathroom and will not be used heavily.

Any thoughts or expereinces who have been using this product specifically or in generall using tankless for a while or any recommendations on other products ?

Any insight is greatly appreciated ..


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## cprao (Oct 26, 2009)

get-a-dog-up-ya said:


> #getadogupya


How did it go ?
Where are you located ? what is your usage ? Did you install the interior one or exterior one ?

can you please share your experience ?


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## md2lgyk (Jan 6, 2009)

I put a Rheem Eco-Sense interior gas tankless in my log home when I built it four years ago. Installed it myself. It's completely hidden in the attic and vents directly out the end wall. One of the best things I did in the house. Unlimited, low-cost hot water and no wasted space. I've never experienced the cold-water sandwich thing.


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## cprao (Oct 26, 2009)

md2lgyk said:


> I put a Rheem Eco-Sense interior gas tankless in my log home when I built it four years ago. Installed it myself. It's completely hidden in the attic and vents directly out the end wall. One of the best things I did in the house. Unlimited, low-cost hot water and no wasted space. I've never experienced the cold-water sandwich thing.


Did you do any maintenance since then ? what is the model you have installed ?

What series of Rheem you have installed ? 95 or 84 ?


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## stephenbbb (Dec 21, 2012)

*Warranty*

Guys,
Do you have gas fitters licenses? I just got a letter from Rheem that in order to honor the warranty i have to prove to them I have followed all local code for the install...


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## Javiles (Dec 12, 2011)

Hope you did-int use any of the galvanize from home depot ??


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## md2lgyk (Jan 6, 2009)

stephenbbb said:


> Guys,
> Do you have gas fitters licenses? I just got a letter from Rheem that in order to honor the warranty i have to prove to them I have followed all local code for the install...


If it passed inspection, it must have been installed to code. Where I live, as long as it passes, they don't care who did the work. A homeowner can do everything for a house but well and septic.


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## stephenbbb (Dec 21, 2012)

*Maintenance*

My neighbor is an inspector for commercial tankless and he says return it. They break down a lot, need expensive maintenance every year (flushing) and after 2 years the model is no longer in production and there are no parts.
I also noticed Rheem does not have a 800 number for customers. 

Any comments?


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## md2lgyk (Jan 6, 2009)

stephenbbb said:


> My neighbor is an inspector for commercial tankless and he says return it. They break down a lot, need expensive maintenance every year (flushing) and after 2 years the model is no longer in production and there are no parts.
> I also noticed Rheem does not have a 800 number for customers.
> Any comments?


Well, my Rheem has not broken down in the four years we've had it. And the manual for mine says nothing about flushing the unit, so I have not done so. What would ever accumulate in a tankless unit that would require flushing?? I know there are issues with tankless units if you have hard water, but I do not.


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## George6488 (Feb 2, 2011)

I have a Tagaki (sp) that has been going strong for 9+ years with not one single problem. It is gas fired.


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## Indyxc (Jan 3, 2013)

If anyone is interested in elec I installed about 3 months ago, a steibel eltron tempura 24 plus.


It rocks. German made, unlike most other Tankless it has a regulating valve that limits flow to make temperature so your water temp is always rock steady no matter the demand it just comps by flowing less.

After a lot of searching I would not recommend rheem. Amazon reviews are helpful, go check different models there. Here is mine:

http://www.manualslib.com/manual/25509/Carrier-58mvp.html?page=3#manual


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## Indyxc (Jan 3, 2013)

md2lgyk said:


> Well, my Rheem has not broken down in the four years we've had it. And the manual for mine says nothing about flushing the unit, so I have not done so. What would ever accumulate in a tankless unit that would require flushing?? I know there are issues with tankless units if you have hard water, but I do not.


Hard water when heated will cause minerals to coat the heating elements in the unit.

Some people like to flush with vinegar or clr one a while to clean the insides.


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## snakej200 (Dec 28, 2021)

Dr. Tankless said:


> A cold water sandwich is caused by the fact that most tankless water heaters work on staging, what this means is that when you first turn on a hot water tap, they go to a pre determined power or BTU output and after a couple of seconds they adjust either up or down, that is why you get a cold water surge or a very hot water surge. Insulating your water lines will have no effect on this staging. Tankless water heaters that have SELF MODULATING technology do not have this issue, you will always have to wait for the water in the lines that have cooled off, but no cold or hot water surge. Any tankless that claims to have this technology MUST have an inlet temperature sensor, and be FLOW ACTIVATED, not flow switch activated and it MUST have a Digital Temperature Setting, and state of the art electroni board, since Modulation is based on several factors. 1. Inlet Water temperature 2. Flow rate and 3. Software that can Instantly combine these 2 factors to produce only the power needed. If the tankless water heater you are considering does not have this technology, you will have inconsistent output temperature, dimming or flickering of your lights if it's electric and if gas same issues. There are many tankless water heaters available today, so do your homework and ask questions to ensure you make the right choice.


Hi I know this is an old thread but I'm just curious if the tankless heater I just installed has these items you describe - Noritz EZ 111 DV-ng. On the spec sheet from the manufacturer it says that it is fully modulating but I know sometimes manufacturers can make a claim that somehow isn't really true.


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