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What would you recommend for a heat-pump water heater?

user-6906608 | Posted in Mechanicals on

Hello. I plan on using a heat pump water heater for my new home No natural gas available where I am having my home built. After some research, looks like a heat pump water heater may be a good choice. I understand that you need a large enough of space (750-1000 cubic feet), to draw air from. I looked at various manufactures, including Rheem, GE, AO Smith, and Stiebel Elton. Rheem list two different types, hybrid electric water heater and hybrid heat pump water heater. Does the later not have a back up electric element? Stiebel Elton goes on about there heat pump water heater that is not hybrid and truly a heat pump and state it is a better system? very expensive. Any recommendations?

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  1. Trevor Lambert | | #1

    I don't think GE makes them anymore, and even if they did, they had a really bad rep for reliability. I bought a used one, and paid appropriately knowing it was a risk, and sure enough it only operates in electric mode.

    If it was me, Stiebel Eltron is too expensive to even be considered, no matter how great they might be.

    That leaves Rheem and AO Smith, and I don't know how I'd differentiate between the two. Unless Rheem just released one that I can't find on the net, all their models are hybrids with electric. I suspect the difference in terminology is just marketing wank differences between consumer and pro product lines.

  2. GBA Editor
    Martin Holladay | | #2

    User 6906608,
    First of all, can you tell us your name? (I'm Martin.)

    In a previous Q&A thread, there was a discussion of what Stiebel Eltron meant when it advertised that it sold "heat pump water heaters, not 'hybrids'." (See screen shot below.) I assumed it meant that these water heaters don't have any electric-resistance elements.

    If my memory serves me well, I think a GBA reader told me that in fact the Stiebel Eltron heat-pump water heaters ARE hybrids, and that their marketing is misleading.

    I found some Stiebel Eltron specs that show that the Accelera 300 E heat-pump water heater from Stiebel Eltron has a rating for "Rated power, booster element" of 1500 watts. That sure sounds to me like an electric-resistance element, which would make it a hybrid.


  3. Trevor Lambert | | #3

    1500W of electric power makes it a hybrid, but a pretty pathetic one, IMO. 1500W is going to take a pretty long time to heat water, given that a typical electric water heater (which are already known for slow water heating) is 3800-4500W. Perhaps this is one case of a manufacturer being honest about their claims. The other brands of hybrids include a full complement of electric heaters (4500W top and bottom).

  4. user-6906608 | | #4

    Sorry Martin, my name is Peter Webb

  5. Steve Knapp CZ 3A Georgia | | #5


    I think Stiebel would argue that you should not buy a heat pump water heater if you will need the booster element on a regular basis. (And thanks for responding to my question on the Rheem HPWH and its options for 15 amp and 30 amp power.)

    Interestingly, I watched a Matt Risinger video recently in which he showed an install that combined a Rheem HPWH with a Rheem Marathon tank. It was an interesting (and costly) solution for meeting intermittent high-demand requirements.

  6. Thomas Stone | | #6

    I installed a GeoSpring in May 2013. It has been working great and uses less than half the energy of my previous electric water heater. All my circuits are monitored with a Brultech GreenEye energy monitor, so I have the data. Bradford White bought the assembly line from GE and markets the unit as the AeroTherm.
    Trevor, did you purchase the original made in China GeoSpring? The one I have (and the ones from Bradford White) are made in the USA.

  7. user-6906608 | | #7

    thanks for the answers everyone

  8. T Carlson | | #8

    I also have a geospring, red top. Works great and we use A LOT of hot water, more than typical for family of four. mM wife is a germ phobe and does a ton of laundry, 2 boys who basically take daily baths/showers because they get filthy running around in dirt piles and myself and wife taking a shower a day min and I take some long showers, my wife takes even longer showers plus I wash the cars with warm water in our garage regularly. Recovery is surprising good, electric bills are great. If the geospring takes a dump I would not hesitate to get another and recomend them to my customers as well in remodels and new construction that can't get nat gas, Im on propane for heat.

  9. Sean W | | #9

    As I understand the marketing behind the Stiebel, they are distinguishing between water heaters that are designed from the ground up to be heat pump water heaters and those that simply place a condenser on top of an electric resistance water heater. Sort of like how Subaru markets their vehicles as being designed around the AWD system, rather than adding AWD to an existing chassis & powertrain. The electric resistance portion is simply there as a backup, if needed, not intended to be used in lieu of the heat pump.

    Maybe I'm wrong on the above, but either way, we are pleased with ours and pleased with how the company has handled a couple of issues that cropped up early on (that's part of what you're paying for). This was on a new build, so we can't compare to the performance of an old unit, but the efficiency is certainly there and it's not nearly as loud as I was anticipating.

  10. Lance Peters | | #10

    What is the cost difference between the Stiebel and the Rheem? The 50 gallon Rheem seems to be a good HPWH value, about $1100 at HD last time I checked, and they claim a COP of 3.5.

  11. Trevor Lambert | | #11

    Rheem is currently $1300 at HD, Stiebel is $2500 (for 58 gal). If you go up to 80 gal, the gap narrows to $2000 and $2600.

    Note that Rheem's "50 gallon" model is actually 45 gallon, and their "65 gallon" model is actually 59 gallon. Kind of sneaky. So it's the 65 gallon Rheem you need to compare to the smaller Stiebel, which is $1650.

    1. Lance Peters | | #13

      That is a bit tricky. However, with the cost difference between the two, you could have two of the Rheem "50" gallon units for a total capacity of 90 gallons for about the cost of the single 80 gallon SE unit. Redundency in case of failure? At best I'd think the double Rheem setup would give much higher heat pump only recovery.

      Does anyone know the standard test conditions under which the Rheem is tested? They claim a COP of 3.5. S-E gives a COP vs. Temperature graph, a much more useful piece of information.

  12. ST Cook | | #12

    AO Smith has the Voltex line of hybrid hot water heaters which are good quality. You can also get the exact same one from State (owned by AO Smith) at sometimes a lower price.

    The GE geospring line stated off a bit bumpy which is unfortunate as it was a great product *once* they fixed the early unit issues, but by then the damage was done. Bradford White "purchased" those assets, so if you want that line (or need parts) start your search with them.

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