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

Pulse
Pulse Member Posts: 51
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?

Comments

  • Larry Weingarten
    Larry Weingarten Member Posts: 2,284
    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. B)

    Yours, Larry
  • Pulse
    Pulse Member Posts: 51
    @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
    hot_rod Member Posts: 15,037
    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.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kcopp
    kcopp Member Posts: 3,821
    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
    hot_rod Member Posts: 15,037
    > @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🤗
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Pulse
    Pulse Member Posts: 51
    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
    Larry Weingarten
  • hot_rod
    hot_rod Member Posts: 15,037
    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 :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Pulse
    Pulse Member Posts: 51
    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
    hot_rod Member Posts: 15,037
    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.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EzzyT
    EzzyT Member Posts: 1,167
    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
    Pulse Member Posts: 51
    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
    EzzyT Member Posts: 1,167
    @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
    Pulse Member Posts: 51
    @EzzyT
    What do you prefer -->
    Crossover floor OR Phoenix light duty
  • Zman
    Zman Member Posts: 6,992
    @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...
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    CanuckerEzzyTkcopp
  • EzzyT
    EzzyT Member Posts: 1,167
    @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
    EzzyT Member Posts: 1,167
    @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
    Pulse Member Posts: 51
    @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
    EzzyT Member Posts: 1,167
    @Pulse either unit will work for your house.
    Pulse
  • hot_rod
    hot_rod Member Posts: 15,037
    The Vesta tankless have a 3 gallon tank built in. The design looks nice, but I have no experience with the brand.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream