# 180 degree tankless for commercial dishwasher



## Protech

What should I use?

The problem: They currently have a lochinvar copper fin 740,000btu boiler cranking out 180 degree water and circulate it through the entire restaurant. This is bad for obvious reasons. They need 180 degree water for the dish washer only. That dish washer only pulls 3gpm or less and has it's own dedicated 3/4" hot water loop running from the boiler room to the dish washer roughly 150' away. 


So I was thinking a tankless unit that could boost the temp from 140(minimum setting of boiler) to 180 would be ideal. The boiler could be turned down to 140 and that would save a ton on fuel and would be easier on the boiler. Currently they have had to replace the boiler every 5 years on the dot.

I guess the ideal thing would be to put the tankless right next to the dish washer as they have space on the wall. That would remove the need for recirc and the associated energy loss. My only concern there is the tankless getting splashed and sucking in grease/smoke/what ever as it's in a commercial kitchen.


What unit would you recommend?

Thanks.


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## Catlin987987

The Navian NP-240 can do 180F


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## Protech

Seems pretty pricey for a 40 degree boost at 3gpm or less.


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## rjbphd

They do make elctric booster heater just for that purpose, under the dishwasher..


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## Protech

Yeah but at $0.12/kwa, they would be spending hundreds of $ a month just on that booster heater. The tankless would pay for it self in a year.

No one makes a 180 degree heater for like $800-$1000?


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## rjbphd

Protech said:


> Yeah but at $0.12/kwa, they would be spending hundreds of $ a month just on that booster heater. The tankless would pay for it self in a year.
> 
> No one makes a 180 degree heater for like $800-$1000?


Ya got a poi t there.. I remmy a drawing where u can piped in serie after the 140 temps heater into a smaller heater set at 180 temps and piped to the DW with return pipe back to small heater.


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## Relic

Do they want to change their set up for two water heaters? You could just offer them a tempering valve installation to temper all but the dishwasher.


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## Protech

Relic said:


> Do they want to change their set up for two water heaters? You could just offer them a tempering valve installation to temper all but the dishwasher.


That's on the table, but that still requires heating the boiler to 180 which is abd for it and not as efficient.


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## pipes

Protech said:


> Yeah but at $0.12/kwa, they would be spending hundreds of $ a month just on that booster heater. The tankless would pay for it self in a year.
> 
> No one makes a 180 degree heater for like $800-$1000?


So if electricy is $0.12/kwa, is gas free? Can we see your calculations for the hundreds a month?
Do you understand how the booster and dishwasher work together and just how much water @180 is needed and for what duration.
A simple booster by Hatco or the like , is the simplest and least expensive way out.
If you are saving them $$$$ on reducing wear and tear as well as fuel on the boiler side they won't notice the spike in electric costs.

I am normally the quiet guy in the back but , I really hate when people try to reinvent the wheel by adding corners to it.


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## Catlin987987

pipes said:


> I am normally the quiet guy in the back but , I really hate when people try to reinvent the wheel by adding corners to it.


With enough corners you can make a wheel


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## johntheplumber

Noritz NC-380


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## Gettinit

pipes said:


> So if electricy is $0.12/kwa, is gas free? Can we see your calculations for the hundreds a month?
> Do you understand how the booster and dishwasher work together and just how much water @180 is needed and for what duration.
> A simple booster by Hatco or the like , is the simplest and least expensive way out.
> If you are saving them $$$$ on reducing wear and tear as well as fuel on the boiler side they won't notice the spike in electric costs.
> 
> I am normally the quiet guy in the back but , I really hate when people try to reinvent the wheel by adding corners to it.


We do this everyday. What's the reason you haven't been chiming in?


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## OldSchool

And you thinks tankless would last ???

Put in a boaster boiler ... AO smith burklay ...

180 is a little on the high side ... We run them at 160


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## pipes

Gettinit said:


> We do this everyday. What's the reason you haven't been chiming in?


I am not the type of person who talks just to hear his own voice, like so many people tend to do.:whistling2:

After better then 25 years in this trade being everything from the hoss to the boss, I have been to the mountain top and met muhammed( or who the F ever) he is as much of a jackazz , as the guy at the bottom of the hill.


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## DesertOkie

pipes said:


> So if electricy is $0.12/kwa, is gas free? Can we see your calculations for the hundreds a month?
> Do you understand how the booster and dishwasher work together and just how much water @180 is needed and for what duration.
> A simple booster by Hatco or the like , is the simplest and least expensive way out.
> If you are saving them $$$$ on reducing wear and tear as well as fuel on the boiler side they won't notice the spike in electric costs.
> 
> I am normally the quiet guy in the back but ,* I really hate when people try to reinvent the wheel by adding corners to it*.



NASCAR added 4 corners and has done pretty well.


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## CC Plumbing

What about the Eternal Heater?


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## OldSchool

What about the tankless sandwich ...


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## Gettinit

pipes said:


> I am not the type of person who talks just to hear his own voice, like so many people tend to do.:whistling2:
> 
> After better then 25 years in this trade being everything from the hoss to the boss, I have been to the mountain top and met muhammed( or who the F ever) he is as much of a jackazz , as the guy at the bottom of the hill.


:notworthy:


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## Gettinit

Hatco is pretty popular. I think they have an energy guide or something on their site. They also have stage heating with their 3 phase boosters. Not sure if they have that option on the smaller ones though. Definitely worth a look as a comparison if nothing else.


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## Greenguy

Instead of adding another boiler to the mix what about leaving the existing water heater at 140°, and installing a booster at point of use. I'm sorry the one I'm used to is from allied, I'm sure others make very similar products: http://alliedboilers.com/products/electric-booster-water-heater/


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## Protech

pipes said:


> So if electricy is $0.12/kwa, is gas free? Can we see your calculations for the hundreds a month?
> Do you understand how the booster and dishwasher work together and just how much water @180 is needed and for what duration.
> A simple booster by Hatco or the like , is the simplest and least expensive way out.
> If you are saving them $$$$ on reducing wear and tear as well as fuel on the boiler side they won't notice the spike in electric costs.
> 
> I am normally the quiet guy in the back but , I really hate when people try to reinvent the wheel by adding corners to it.


I don't have the price per therm of natural gas memorized but i do know that it's about 1/3 the cost of electricity generally. This is a buffet restaurant and that dishwasher runs more or less non-stop from 12 hours a day. You do the math. That's hundreds of $ a month in electricity if they were to use an electric booster.

As I said earlier, dish washer uses 2-3 fpm at 180F.


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## Protech

Greenguy said:


> Instead of adding another boiler to the mix what about leaving the existing water heater at 140°, and installing a booster at point of use. I'm sorry the one I'm used to is from allied, I'm sure others make very similar products: http://alliedboilers.com/products/electric-booster-water-heater/


That seems like it would be expensive to purchase and install since I would have to run a 20-40 amp circuit 150' across a commercial kitchen and then expensive to run because it's electric.

There is already a recirc loop running from the boiler room and a gas line an electrical panel next to it. Gas tankless seems like the obvious choice for lowest life cycle cost.


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## pipes

Protech said:


> I don't have the price per therm of natural gas memorized but i do know that it's about 1/3 the cost of electricity generally. This is a buffet restaurant and that dishwasher runs more or less non-stop from 12 hours a day. You do the math. That's hundreds of $ a month in electricity if they were to use an electric booster.
> 
> As I said earlier, dish washer uses 2-3 fpm at 180F.


I know you think tankless heaters are the coolest thing since the pipe wrench but, without some hard numbers you are guessing. Believe it or not I am trying to help you.
Do you really know how much water you need at 180? ( this would entail learning about how the dishwasher works and timing of the cycle) Please don’t just repeat yourself with 2 -3 gpm. There is a reason I am pushing this question, I just might know more about this than you.
If you can prove that a tankless heater is the better way ( meaning in the best interest of your customer in cost of installation, maintenance , longevity and fuel consumption) I will humbly apologize.


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## Plumbducky

I did one like you want to do with a Noritz and a storage tank with an aquastat and pump. The tankless can keep up but it takes a handful of cycles for the dw to fully get up to temp, since the dw has 3 storage tanks in it for each of the stages. The dw uses about 2.3 gpm and the tankless puts out 2.6 gpm.

Good luck.


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## Protech

pipes said:


> I know you think tankless heaters are the coolest thing since the pipe wrench but, without some hard numbers you are guessing. Believe it or not I am trying to help you.
> Do you really know how much water you need at 180? ( this would entail learning about how the dishwasher works and timing of the cycle) Please don’t just repeat yourself with 2 -3 gpm. There is a reason I am pushing this question, I just might know more about this than you.
> If you can prove that a tankless heater is the better way ( meaning in the best interest of your customer in cost of installation, maintenance , longevity and fuel consumption) I will humbly apologize.


It's clear you know nothing about me, my business, or what I'm about. If you have a recommendation on what tankless unit to use, I'm all ears. Otherwise, would you kindly bugger off and quit trolling my thread, new bee?


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## Catlin987987

Protech said:


> It's clear you know nothing about me, my business, or what I'm about. If you have a recommendation on what tankless unit to use, I'm all ears. Otherwise, would you kindly bugger off and quit trolling my thread, new bee?


He's only trying to get some more info, he's right research is what might be needed.


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## pipes

Protech said:


> It's clear you know nothing about me, my business, or what I'm about. If you have a recommendation on what tankless unit to use, I'm all ears. Otherwise, would you kindly bugger off and quit trolling my thread, new bee?


Lmao, newbee, is that your best? I was here before you. 
Don't get your panties in a bunch there Sally, Instead of getting angry with me try to prove me wrong. 
I really did not intend to start a p!ssing or name calling contest, I just wanted you to stop and open your eyes.
You can dress in hospital garb, pipe in the prettiest ways possible but, if you cannot explain the how and why of what we do, you are no better than the guys who drag this trade down with shotty work.

Later sweetheart, have a nice day :thumbsup:


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## Protech

2gpm average flow over 12 hours average=1440 gallons per day at 40 degree rise.

At $0.12 kWh = $12,421 per year.

Even if we assume the usage is only 1/10 of that, it's still painfully obvious the electricity is not a cost effective fuel source. Therefor, a gas heater is the only viable option here for lowest life cycle cost.

Now, can we back to a serious discussion on the best way to do this?


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## pipes

Thank you, I just wanted you to start using your brain. 
Hears a tid bit of info you should verify in your situation, the dishwasher uses 150 degree water for the bath and only uses short bursts (10 seconds or so in each cycle of 60 to 90 second long cycles )of 180 degree to sanitize. So not only is the amount a factor but , the duration of the rinse cycle.
Next we can debate maintenance and longevity.:thumbup:


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## Protech

pipes said:


> Thank you, I just wanted you to start using your brain.
> Hears a tid bit of info you should verify in your situation, the dishwasher uses 150 degree water for the bath and only uses short bursts (10 seconds or so in each cycle of 60 to 90 second long cycles )of 180 degree to sanitize. So not only is the amount a factor but , the duration of the rinse cycle.
> Next we can debate maintenance and longevity.:thumbup:


So what, you're proposing running a branch on the loop to the heater and having a 140 connection for everything but rinse. Tankless runs only the rinse? Seams like a lot of work for very little benefit.


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## Protech

pipes said:


> Thank you, I just wanted you to start using your brain.
> Hears a tid bit of info you should verify in your situation, the dishwasher uses 150 degree water for the bath and only uses short bursts (10 seconds or so in each cycle of 60 to 90 second long cycles )of 180 degree to sanitize. So not only is the amount a factor but , the duration of the rinse cycle.
> Next we can debate maintenance and longevity.:thumbup:


You seem to know a lot about the dishwashers operation without actually knowing which model I'm working with. How is that?


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## pipes

Protech said:


> So what, you're proposing running a branch on the loop to the heater and having a 140 connection for everything but rinse. Tankless runs only the rinse? Seams like a lot of work for very little benefit.


I am only trying to get you to think like a true professional, look at the whole picture.
I learned about them through plumbing 23 restaurants when I was self employed. Now I deal with maintaining 15 of them from single to triple bay units.


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## Protech

pipes said:


> I know you think tankless heaters are the coolest thing since the pipe wrench but, without some hard numbers you are guessing. Believe it or not I am trying to help you.
> Do you really know how much water you need at 180? ( this would entail learning about how the dishwasher works and timing of the cycle) Please don’t just repeat yourself with 2 -3 gpm. There is a reason I am pushing this question, I just might know more about this than you.
> *If you can prove that a tankless heater is the better way ( meaning in the best interest of your customer in cost of installation, maintenance , longevity and fuel consumption) I will humbly apologize.*


Still waiting on that.

I don't know if you realize this but, you appear very cocky. You (a new basically unknown new bee) chime in on a thread by a well vetted member talking down to him. You then claim his idea is stupid and then recommend something else that is in fact the opposite thing that you later claim was your intent.

Then you act as if you are somehow the superior, more experienced authority on the subject.


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## Protech

So I'm thinking a Navien NPE180A would be the ticket. Opinions?


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## U666A

Protech said:


> Do you have any idea who I think I am?!?.


:jester: Just kidding PT, carry on.


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## Relic

Pipes I think you stepped in the doodoo on this one lol. Best thing to do is, humbly say "you're right Protech"

No harm in being humble.


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## Protech

The NPE180A is condensing, can put out 180F and can run on recirc so that seems like the ticket, no?


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## rjbphd

Protech said:


> The NPE180A is condensing, can put out 180F and can run on recirc so that seems like the ticket, no?


Maybe... how far and size will u have to run the gas pipe?? I've seen blk pipe get coroded in area of dishwasher,let alone the tankless if it will be installed in vicinty(sp)


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## Protech

rjbphd said:


> Maybe... how far and size will u have to run the gas pipe?? I've seen blk pipe get coroded in area of dishwasher,let alone the tankless if it will be installed in vicinty(sp)


Oh no, I was thinking about just putting it in the boiler room since there is already a recirc loop and pump right next to the gas line feeding the boiler.


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## rjbphd

Protech said:


> Oh no, I was thinking about just putting it in the boiler room since there is already a recirc loop and pump right next to the gas line feeding the boiler.


Gotcha... and of course u'll need the temp gage on the outlet, screw the alt needle gage..lol


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## SewerRatz

I would go with a Noritz, their standard commercial units can put out 180℉ with out any issues.

All the places I do work at have tankless heaters putting out 150℉ water and use the dishwashers heater booster to make the 180℉ water which is needed for the final sanitizer rinse. Some of the places waive the heater booster and use a chemical sanitizer in the final rinse.


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## rjbphd

SewerRatz said:


> I would go with a Noritz, their standard commercial units can put out 180℉ with out any issues.
> 
> All the places I do work at have tankless heaters putting out 150℉ water and use the dishwashers heater booster to make the 180℉ water which is needed for the final sanitizer rinse. Some of the places waive the heater booster and use a chemical sanitizer in the final rinse.


True.. but careful with the chemical sanitizer and the ph of water will etch the glassware to hell


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## Gettinit

Do not spend the extra money on the condensing heater. It will not condense at those temps.


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## Protech

SewerRatz said:


> I would go with a Noritz, their standard commercial units can put out 180℉ with out any issues.
> 
> All the places I do work at have tankless heaters putting out 150℉ water and use the dishwashers heater booster to make the 180℉ water which is needed for the final sanitizer rinse. Some of the places waive the heater booster and use a chemical sanitizer in the final rinse.


There is no booster on the dishwasher. that's why the main boiler is running at 180f.


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## newyorkcity

How far is the boiler room? What about temperature drop from the heater to the dishwasher. 1" fiberglass insulation?


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## SewerRatz

Protech said:


> There is no booster on the dishwasher. that's why the main boiler is running at 180f.


The boosters the customers I have are technology separate from the machine, it's on a stand under the table were the dishtrays come out of the machine.


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## Protech

newyorkcity said:


> How far is the boiler room? What about temperature drop from the heater to the dishwasher. *1" fiberglass insulation?*


Yep


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## Protech

SewerRatz said:


> The boosters the customers I have are technology separate from the machine, it's on a stand under the table were the dishtrays come out of the machine.


Right, and this dishwasher doesn't have one. If I were to put one in electrical would have to be run.


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## SewerRatz

Also if you run a recirc pump on the tankless unit, be sure to put an aquastat on it to turn the pump off when the return line is hot enough. Also put a timer on it to turn the pump off during non-work hours.


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## rjbphd

SewerRatz said:


> Also if you run a recirc pump on the tankless unit, be sure to put an aquastat on it to turn the pump off when the return line is hot enough. Also put a timer on it to turn the pump off during non-work hours.


 As well do not oversized the return pump for (&^{%&#sake!


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## pipes

Protech said:


> Still waiting on that.


You will get it when you finish the challenge I presented in* full*.
Relic, rj you piped in help him teach me.
I never said it could not be done with a tankless, my point is it is not truly worth it on an existing kitchen.
So far I have ....... _it is cheaper to heat water with gas compared to electricy_..... oooh I better write that down.

Please gentlemen hard numbers , the whole picture , apple vs. apple.


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## SewerRatz

pipes said:


> You will get it when you finish the challenge I presented in* full*.
> Relic, rj you piped in help him teach me.
> I never said it could not be done with a tankless, my point is it is not truly worth it on an existing kitchen.
> So far I have ....... _it is cheaper to heat water with gas compared to electricy_..... oooh I better write that down.
> 
> Please gentlemen hard numbers , the whole picture , apple vs. apple.


 
Hi TheMaster, long time no see.:whistling2:


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## pipes

SewerRatz said:


> Hi TheMaster, long time no see.:whistling2:


LMAO,..wait a minute, is this where I should whine or run away ?


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## Mississippiplum




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## Protech

Gettinit said:


> Do not spend the extra money on the condensing heater. It will not condense at those temps.


who cares. they will still operate at maximum efficiency.


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## Gettinit

Protech said:


> who cares. they will still operate at maximum efficiency.


Maximum efficiency would be condensing. They will not condense. If it were any where near condensing you would be about 85% AFUE. You will get the same efficiency as the standard tankless units and save some money. Plus, you cannot clean the ss heat exchanger with the same chemicals out there for copper heat ex hangers.


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## Protech

Gettinit said:


> Maximum efficiency would be condensing. They will not condense. If it were any where near condensing you would be about 85% AFUE. You will get the same efficiency as the standard tankless units and save some money. Plus, you cannot clean the ss heat exchanger with the same chemicals out there for copper heat ex hangers.


The lack of condensation when starting from 140 and boosting to 180 does not equal less than 85% efficiency (I'm pretty sure). Please cite a credible source for your claim.

A SS heat exchanger can be cleaned using an acetic acid solution no problem.


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## Gettinit

Protech said:


> The lack of condensation when starting from 140 and boosting to 180 does not equal less than 85% efficiency (I'm pretty sure). Please cite a credible source for your claim.
> 
> A SS heat exchanger can be cleaned using an acetic acid solution no problem.


OK. I do not have a customer that has one operating above 180° F so I cannot just pop a probe in there to get a combustion analysis. I did call Rinnai for you. Engineering said right off the bat they do not want you to use their tankless heaters as boosters. They are not designed for it period. The fact that the DW needs it there before the heaters are capable of sensing it to then put out the demand.

As far as the analysis goes they do not have any documents either but agreed that you would nit be as high as 85% AFUE.

Hope this helps.


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## Gettinit

Protech said:


> The lack of condensation when starting from 140 and boosting to 180 does not equal less than 85% efficiency (I'm pretty sure). Please cite a credible source for your claim.
> 
> A SS heat exchanger can be cleaned using an acetic acid solution no problem.



Just fyi, I am not trying to be a smart a$$, just trying to help.....
As far as a credible source...I have been tuning boilers for a while now. I tune all kinds including high end condensing boilers. While they are not tankless I do know the relationship between firing rates, incoming temps, boiler temps and their AFUE in general. If you want a more credible source maybe you should discuss this with your brother or tag along when he is doing an analysis.

Oh, I had no clue about that particular acid for ss. Would it mess up the copper heat exchanger?


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## SewerRatz

The tankless heaters are more than capable to go from 45℉ water to 180℉ water that will meet the demand of the dishwasher. So instead of using a tankless heater as a booster, use it as a dedicated heater.


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## SewerRatz

Gettinit said:


> Oh, I had no clue about that particular acid for ss. Would it mess up the copper heat exchanger?


Any phosphoric based acid which most tankless cleaners use will not harm stainless steel or copper. AO Smith has Un-Lime which is used on all their water heaters including coil type boilers. Flow-Aid by Stiebel Eltron works really well. Speed clean makes one called SpeedyBright. Pretty much same as the others I listed.


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## justme

SewerRatz said:


> The boosters the customers I have are technology separate from the machine, it's on a stand under the table were the dishtrays come out of the machine.


This is the only way we do commercial dishwashers , we set the main boiler at 140 degrees then we install an electric booster heater under the table of the dishwasher that will get the water to 185 degree's.


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## Gettinit

SewerRatz said:


> The tankless heaters are more than capable to go from 45℉ water to 180℉ water that will meet the demand of the dishwasher. So instead of using a tankless heater as a booster, use it as a dedicated heater.


I think this may be what Pipes was eluding to. You have a very very tight window of the DW wants it now or it will not sanitize. And after talking to the engineer they seem to have it in writing somewhere so if something were to happen, or not happen, you are caught with your pants down. The engineer even said, that's why they make booster heaters. I know Protech is wanting to help out his customer to the best of his ability but I think he would be reaching too far. I say let the electrician run the wiring and save face later because god knows he will not be getting the big attaboy if it works.


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## justme

Here's what we use. http://www.basequipment.com/C-24-6-Gallon-Booster-Water-Heater-p/hat-c24.htm


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## Gettinit

SewerRatz said:


> Any phosphoric based acid which most tankless cleaners use will not harm stainless steel or copper. AO Smith has Un-Lime which is used on all their water heaters including coil type boilers. Flow-Aid by Stiebel Eltron works really well. Speed clean makes one called SpeedyBright. Pretty much same as the others I listed.


I have seen pictures of a cut up heat exchanger. If it is similar to Rydlime it will grow this fungus looking stuff inside and you have to replace it. Please believe me. I have seen it with my own eyes at the manufacturers building.

While some manufacturers say not to do something because it was yet to be tested I have seen the aftermath.


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## SewerRatz

Gettinit said:


> I have seen pictures of a cut up heat exchanger. If it is similar to Rydlime it will grow this fungus looking stuff inside and you have to replace it. Please believe me. I have seen it with my own eyes at the manufacturers building.
> 
> While some manufacturers say not to do something because it was yet to be tested I have seen the aftermath.


 
I have been using Un-Lime for 20 years now on boilers, tank heaters and the last 10 years on tankless. No issues what so ever. I did have a pinhole leak on a Noritz heat exchanger, but it was at the point where they brazed on a tab to mount one of the heat sensors. The Noritz Engineer had me cut the old one in half. It looked like the day it was installed, which earned me a congratulations from the Engineer saying I been doing my job properly deliming the units.

So tell me what do you use to delime a unit with stainless steel and copper heat exchangers? Phosphoric acid is used by the water heater industry (Un-Lime) to delime their tank, tankless, and boilers. It is also used by Soda companies as the third to fourth ingredient in soda pop and I been in one of the processing places, they use stainless steel process piping.


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## SewerRatz

justme said:


> Here's what we use. http://www.basequipment.com/C-24-6-Gallon-Booster-Water-Heater-p/hat-c24.htm


That is pretty much the unit I have seen in all the restaurants I have been in.


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## SewerRatz

This site in the UK has a few differnet descaling chemicals. This one which if you read the MSDS it is phosferic acid, and they say it is safe for steel, stainless steel, cast iron, brass and copper. http://www.kamco.co.uk/FX.html

Where this one http://www.kamco.co.uk/HD.html they say is not to be used with stainless steel it is hydrochloric acid based.


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## AMERICAN ROOTER

I don't know what the health codes are in you're state. They let us use 140 water temp. with a chemical rinse for commerical dishwashers.


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## Relic

AMERICAN ROOTER said:


> I don't know what the health codes are in you're state. They let us use 140 water temp. with a chemical rinse for commerical dishwashers.


How about an introduction.


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## rjbphd

AMERICAN ROOTER said:


> I don't know what the health codes are in you're state. They let us use 140 water temp. with a chemical rinse for commerical dishwashers.


Who are you again panning in here without a proper full intro??


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## PLUMBER_BILL

Protech said:


> What should I use?
> 
> OTHERS HAVE ASKED ... AND THE REPLY ABOUT 180?
> 
> CHEMICAL INJECTORS INSTEAD ...
> 
> http://www.plbg.com/forum/read.php?1,258436


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## Gettinit

SewerRatz said:


> This site in the UK has a few differnet descaling chemicals. This one which if you read the MSDS it is phosferic acid, and they say it is safe for steel, stainless steel, cast iron, brass and copper. http://www.kamco.co.uk/FX.html
> 
> Where this one http://www.kamco.co.uk/HD.html they say is not to be used with stainless steel it is hydrochloric acid based.


That's why I said if it were like Rydlime (hydrochloric acid based) not to use it. I am not claiming to know everything, that is why I made mention of it. :thumbup:

Check your PM in a bit.


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## Protech

Gettinit said:


> OK. I do not have a customer that has one operating above 180° F so I cannot just pop a probe in there to get a combustion analysis. I did call Rinnai for you. Engineering said right off the bat they do not want you to use their tankless heaters as boosters. They are not designed for it period. The fact that the DW needs it there before the heaters are capable of sensing it to then put out the demand.
> 
> As far as the analysis goes they do not have any documents either but agreed that you would nit be as high as 85% AFUE.
> 
> Hope this helps.


I'll do a combustion analysis after I put the Navien in and we will both find out.


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## Protech

PLUMBER_BILL said:


> Protech said:
> 
> 
> 
> What should I use?
> 
> OTHERS HAVE ASKED ... AND THE REPLY ABOUT 180?
> 
> CHEMICAL INJECTORS INSTEAD ...
> 
> http://www.plbg.com/forum/read.php?1,258436
> 
> 
> 
> They don't want to use chemicals as they do such high volume it's not economical.
Click to expand...


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## Gettinit

Protech said:


> I'll do a combustion analysis after I put the Navien in and we will both find out.


You will need to run a hose somewhere and make sure it doesn't run too much volume to be accurate. The DW will not likely run long enough to get a stable reading. I hope you prove us wrong. :thumbsup:


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## ZL700

Operating a Navien with a 140 inlet raising temp to 180 it will likely be in the 80%-84% thermal \ combustion efficiency. However it would still make sense to use the Navien for ease of venting and building circulation to the dishwasher.
Efficiencies aside, I doubt you could buy and vent and add a circ to a standard tankless and be less $ than the Navien in the end.


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## AMERICAN ROOTER

Relic said:


> How about an introduction.


 I don't have cool glasses but I have tidy whites I was in the loco 178 plumber pipefitters Springfield Mo. During the Branson Gigg. And still plumbing IT. And I don't need no stinking CARD:thumbsup:


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## Gettinit

AMERICAN ROOTER said:


> I don't have cool glasses but I have tidy whites I was in the loco 178 plumber pipefitters Springfield Mo. During the Branson Gigg. And still plumbing IT. And I don't need no stinking CARD:thumbsup:


Click the link, read the the first sticky and the announcement at the top. Then you will get what/why he posted the link. It is easy.


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## rjbphd

AMERICAN ROOTER said:


> I don't have cool glasses but I have tidy whites I was in the loco 178 plumber pipefitters Springfield Mo. During the Branson Gigg. And still plumbing IT. And I don't need no stinking CARD:thumbsup:


Yea, sounds like a loco and non plumber without the proper intro in the intro section.


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## pipes

Let’s try a different approach. Can I ask questions with a low post count or is that trolling too?
The Lochinvar, failing so quickly, is it sized properly for the load? Over? Under? 
Is the pump sized properly? Is the boiler and/or hot water system piped properly? Is it firing properly?
Has there been proper maintenance? Is it in a poor quality environment?
All questions older plumbers would be asking.
Next , your new booster system , being it is located 150’ away you are recirculating it.
What would your temperature differential be? Being you must maintain 180 degrees at your point of use and most tankless water heaters top out at 185 degrees.
How much water are you keeping at 180 degrees in standby? Being your suggested loop is approximately 300’ long, plus the heater.
What is your estimated gas usage? ( if you can estimate electric , you can estimate gas)
Which manufacturer recommends there product to be used in this application?


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## CaberTosser

My thinking is to take a peek into wastewater heat recovery from the downstream side of the dishwasher, perhaps you can incorporate a double-wall heat exchanger from the discharge water to preheat the cold water supply to the water heater. All energy sources are expensive when you simply throw away perfectly viable BTU's.


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## Plumbworker

most chemical dishwashers only need 120 min.. in fact i've seen conventional commercial dishwashers converted to chemical... i also would sue the **** out of them when i go to wash my hands in the bathroom after my meal..

Thats one thing i always check when i eat out is if they have tempered the bathroom water most are running high temps to the bathrooms... inspectors need to ensure the have a high temp and low temp piping!


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## Gettinit

Plumbworker said:


> most chemical dishwashers only need 120 min.. in fact i've seen conventional commercial dishwashers converted to chemical... i also would sue the **** out of them when i go to wash my hands in the bathroom after my meal..
> 
> Thats one thing i always check when i eat out is if they have tempered the bathroom water most are running high temps to the bathrooms... inspectors need to ensure the have a high temp and low temp piping!



I believe its 135°F...


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## Plumbworker

Gettinit said:


> I believe its 135°F...


Not the last one i piped in it was rated 120 degree min.. no booster needed... I Actually had one client that was sued because a customer was burned from the 180 dhw from a lavy faucet for whatever reason the city signed them off without checking dual temp system or tempering valves.. I ended up installing those under counter mixing valves under every public and hand wash fixture..


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