Stainless 2-5 gallon buffer/storage tank for tankless?

Pulse

I know Navien and Westinghouse/HTP both have "hybrid" models with a small storage tank, however, Navien is not available in my area and Westinghouse/HTP's model does not seem to get very good reviews.

So, I was thinking about using a small tank to eliminate the cold water sandwich. Do any companies make something like this?

Larry Weingarten

Hi, This has been a rather thorny question. People have tried using a small electric tank in series with the tankless, which can work as long as no recirculation system is used. Recirc winds up being a huge heat loss, running the electric element a lot.

If the tank isn't electrically heated, how do you move heat from the tankless unit into the tank?

If you do this, a small 120 VAC glass lined tank is fine as long as you check the anode periodically. Also it might be easier to find than a small stainless tank that can do the job.

Lastly, will the small tank combined with tankless actually save significant energy? I'm assuming you're going tankless for that reason.

Yours, Larry

Pulse

@Larry Weingarten

Yeah, I honestly do not know, I was just trying to get the best of both worlds. I definitely do not want to purchase an electric tank for a tankless.

There is also this:
https://www.homedepot.com/p/Westinghouse-50-Gal-Ultra-High-Efficiency-High-Output-10-Year-76-000-BTU-Natural-Gas-Water-Heater-with-Durable-Stainless-Steel-Tank-WGR050NG076/205625740

..also known as the HTP Phoenix Light Duty.

Its actually more than a tankless and only has a 10yr warranty compared to an average of ~15yrs on tankless.

What are the thoughts on that model?..do any other manufactures make something similar?

hot_rod

I think HTP has a 5 gallon stainless tank, maybe in their Marine offering. I'd consider one of these 2-1/2 gallon tanks, even has an element for backup. They are usually in a foam clamshell insulation for low heatloss.

kcopp

That's funny.
I just did this very thing today and yesterday for 2 customers who were tired of waiting for hot water at the kitchen sink. Both had rinnai water heaters.
No recirc.
I installed a 2.5 gal Emax tank to eliminate the cold sandwich and the wait time.
You are right @Larry Weingarten about the anode. Especially the bosch one... anode is about as thick as a pencil. They need to do better w/ this.

hot_rod

> @kcopp said:
> That's funny.
> I just did this very thing today and yesterday for 2 customers who were tired of waiting for hot water at the kitchen sink. Both had rinnai water heaters.
> No recirc.
> I installed a 2.5 gal Emax tank to eliminate the cold sandwich and the wait time.
> You are right @Larry Weingarten about the anode. Especially the bosch one... anode is about as thick as a pencil. They need to do better w/ this.

I think those early 2-1/2 heaters were copper tanks, are they stainless now?

Wasn’t until recently we started seeing anodes in stainless indirects.

I think HeatFlo was the first brand SS tank that I noticed with an anode. I think most Ss indirects are anode free?

I think Eemax has an even small point of use electric heater, maybe in the 1-1/2 gallon range

Nice fix for those customers🤗

Pulse

hot_rod said:

I think HTP has a 5 gallon stainless tank, maybe in their Marine offering. I'd consider one of these 2-1/2 gallon tanks, even has an element for backup. They are usually in a foam clamshell insulation for low heatloss.

They did have a 6 gallon under marine, but sadly looks like it was discontinued. --> http://www.htproducts.com/literature/lp-13.pdf

So, an electric point of use or an ES4 electric tank are the only options

think i may just eliminate the tankless and go for a hybrid

hot_rod

I wonder if a tank like this would work. Originally designed to prevent legionella growth with flow thru design.

Try one out and let us know

Pulse

hot_rod said:

I wonder if a tank like this would work. Originally designed to prevent legionella growth with flow thru design.

Try one out and let us know

those would certainly be an option, i dont know how I feel about the EPDM rubber, i dont want the cancer...haha

hot_rod

Pulse said:

hot_rod said:

I wonder if a tank like this would work. Originally designed to prevent legionella growth with flow thru design.

Try one out and let us know

those would certainly be an option, i dont know how I feel about the EPDM rubber, i dont want the cancer...haha

I imagine your water touches other EPDM before it gets to you.
It is NSF listed and if they are used in California I'd guess they have other health safety requirements or notifications like Prop 65.

EzzyT

HTP has the Crossover Tank which is 20 gallons and a hybrid unit which are also high efficient condensing.
We’ve installed a bunch of them and they work really well. There equivalent to a standard 50 gallon power vent water heater.

Pulse

EzzyT said:

HTP has the Crossover Tank which is 20 gallons and a hybrid unit which are also high efficient condensing.

We’ve installed a bunch of them and they work really well. There equivalent to a standard 50 gallon power vent water heater.

How long have you been installing them?, like what is the oldest one you have seen still going strong?

That 20 gallon one is cool, but its more than the crossover and only has a 6 year warranty for some reason..

EzzyT

@Pulse I think HTP came out with that unit 4-5 years ago and the oldest one we installed was about that long ago.

Pulse

@EzzyT
What do you prefer -->
Crossover floor OR Phoenix light duty

Zman

@Pulse
I am curious which reviews you are referring to?

I find that most websites reviewing products are written by non-tech folks that are just creating websites in order to extract money from the manufacturer's marketing departments.

Most of the consumer feedback appears to be homeowners with an ax to grind. They are usually blaming the manufacture for the work of the incompetent installer that the owner hired.

If there s a good one out there, I would love to know about it...

EzzyT

@Pulse we installed plenty of both the Crossover and Phoenix light duty and great results from both.
It’s all depends on the application.
The plus side of the Phoenix is that it can be used as a combi unit for heating on a hydro-coil since it has the side tappings for that application.
Need to know more details on your application in order to determine which unit would work best for you.
How many full and half bathrooms?
Shower heads, hand held shower sprays, body sprays and rain heads?

EzzyT

@Zman i completely agree with you statement.
We get those comments all the time regarding equipment we proposed to install. When one really finds out the truth about the BS reviews that are given online is that the equipment was never installed properly nor maintained on a regular basis. Plus most of the equipment being installed by these companies don’t know how to properly maintain and diagnose the equipment if there is a failure and are just part swappers.

Pulse

@Zman
I was referring to the HTP tankless Crossover wall reviews, but yes, they are from homeowners

@EzzyT
2 full, 1 half bath, each shower has a rain head with normal hand held sprayer

I am leaning towards the Phoenix LD. There is only ~$100 increase over the crossover floor.

EzzyT

@Pulse either unit will work for your house.

hot_rod

The Vesta tankless have a 3 gallon tank built in. The design looks nice, but I have no experience with the brand.

Nurit

kcopp said:

I just did this very thing today and yesterday for 2 customers who were tired of waiting for hot water at the kitchen sink. Both had rinnai water heaters.
No recirc.
I installed a 2.5 gal Emax tank to eliminate the cold sandwich and the wait time.

hi kcopp,
Did you install the 2.5gal Emax tank before or after the Rinnai? I have a Navien NCB-240 ASME combi-boiler with the same problem, and I'm looking at EccoTemp's SmartHome electrical mini-tanks.

thanks,
Nurit