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Product Guide

A Look at State Premier’s New Heat Pump Water Heater

The redesign of a previous model adds features and flexibility

For the past seven years, my go-to heat pump water heater has been the State Premier Hybrid Electric. It comes in three sizes, 50, 66, and 80 gallons, and has performed solidly for my company. With it, we’ve helped hundreds of customers electrify their water heating and reduce their carbon footprint.

State Water Heaters are part of the A.O. Smith family of companies. A.O. Smith sells similar models under its label and other brands, including American, Lochinvar, Reliance, and U.S. Craftmaster.

I was excited to learn that, in fall 2022, A.O. Smith introduced an updated model, labeled variously the A.O. Smith Voltex AL Smart Hybrid Electric and the State Premier AL Hybrid Electric. The “AL” stands for its built-in “anti-leak” sensor. The new version features higher efficiency, lower noise ratings, wireless connectivity, and a “smart anode” for corrosion protection. It also incorporates changes to its layout that make it easier to install.

We’ve installed several of the new models and have been quite happy so far. Here I’ll look at how it differs from its predecessor and touch on newly published space requirements for heat pump water heaters.

Physical dimensions, layout, and clearances

The older 50-gal model is 22 in. wide by 63 in. tall; the 66- and 80-gal models are 27 in. wide and 61 in. and 69 in. tall, respectively. The new units are all within ½ in. of these dimensions. Despite these similarities in overall size, the new models incorporate design changes that allow for tidier installations and more flexibility in location:

Potable water connections. In the older model, the cold water inlet and hot water outlet are both on the side of the unit. Since most tank-style electric, natural gas, and propane water heaters have connections on the top, installing the older model means extending piping downward. The…

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  1. Deleted | | #1


    1. Jon_Harrod | | #4

      I'm not the best at evaluating sound levels--too much loud music and lack of ear protection in my youth. I had planned to get some decibel measurements in the field but didn't get to it before my deadline. I'll try to get some and post them.

      1. Deleted | | #5


  2. Cafferatak2 | | #2

    I'm on a tight power budget. Do you have a lower power model like REEM does? or plans for one?
    I'm talking peak power usage not average. It looks like the only option on this one is 4500 W.
    Really happy to see folks working to advance this technology - Thank you!

    1. Jon_Harrod | | #3

      The only 120V models I know about are made by Rheem, though I expect we'll see more options in the next few years.

    2. acrobaticnurse_Eli | | #8

      If you're ok with 240v but just need lower wattage most electric water heaters allow you to switch out the heating elements with virtually all except the Rheem Marathon using the same standard size. A 4500 watt element could be switched out for a 3000 watt element in a few minutes. The manual details replacing a heating element and it looks the same as most any other electric water heater. Going down in wattage is generally a non-issue, you just don't want to go above the provided rating. Another option would be to keep the water heater in heat pump only mode. I haven't seen anything listing the watt draw of the heat pump but would expect it to be less than 4500.

  3. ArchitectJudge | | #6

    This looks like a great piece of equipment! I'll need 80 gallon, and its coming in at $2,800 at my local supply house. Do you have any recommendations for a simliar 80 gallon electric HP water heater that has a UEF of 2.9 (or higher) that is a bit more affordable (requirement for energy credit)? Always a balance of features/efficiency and cost!

    1. Jon_Harrod | | #7

      Unfortunately, I don't have a good alternative. There seems to be a big price premium for the 80-gallon models, about $1000 over the 50-gallon even though I believe the electronics and heat pump components are almost all the same. Are there any state or utility incentives you could use to augment the Federal tax credit?

  4. AndyKosick | | #9

    I was just next to one of these on Tuesday. I was able to measure db using the NIOSH smart phone app and got 47.7 db. Importantly the sound is fairly pleasant, not all sounds are created the same. No significant compressor buzz, mostly soft air like noises and gentle hum. High hopes for this model since noise has been the most significant draw back for HPWHs.

    1. Jon_Harrod | | #15

      I did some similar testing this week. My older model, installed in 2020, registered about 54 db at 1 meter from the front and sides and 59 db at 0.5 m over the unit. The new model I tested generated about 44 db on the front and sides and 53 db on top. I agree, the sounds from the new model are pretty benign.

  5. acrobaticnurse_Eli | | #10

    I wonder how readily a powered anode could be added. For most electric water heaters it's about as simple as replacing a sacrificial anode and having a nearby outlet to plug it in. With the heat pump condenser on top of the tank and in the way of accessing the anodes would much modification be needed to install an anode that would have a power cord coming out the top of the tank?

  6. nickdefabrizio | | #11

    I installed the 50 gal model two years ago. It has been working fine since then. I do get some rotten egg smell so the powered anode would have been great. Of the other changes, the longer run time on electric mode would be good for deep winter when I want to reduce the cooling load on my basement mini split heat. However, this is not a big deal and I only switch to all electric on very rare occassions. Of course there are only two of us and we use very little water.

    I recall that it was easy to install and only took me a few hours, including running a new 30 amp circuit. On the other hand, I had to replumb the entire hot water line and cold water feed since the existing plumbing was set up for a boiler hot water system on the other side of the room. However, people who are replacing an existing hot water tank system will likely have the proper plumbing in place.

    I am a bit shocked at the price now. I bought mine 2 years ago from Lowes as a return for $700 and got a $750 rebate from the state. They also had a returned 80 gal model for $900. I should have picked up that one too! I think the list price at that time was $1300 for the smaller unit and a little more for the 80 gal unit. People paying $2000-3000 is shocking!

  7. Trevor_Lambert | | #12

    Sound levels are reported on a logarithmic scale because that's how our hearing works. It's of no practical value, and in fact misleading to mention that a 6dB reduction represents a 4-fold reduction in noise energy. It implies the reduction in perceived noise will be greater than it is in reality. And a smaller nitpick is that the A in 51dBA is a frequency response weighting. It's nonsensical to report a relative difference of 6dBA, it's just 6dB.

  8. mercifullyfree | | #13

    From personal experience (approximately 2 years ago) and the shared experience of the very knowledgeable technician who assisted me when our unit failed after a few days:
    1 - Apparently a wiring harness is routed directly above the water tank and is a cause of frequent failure.
    2 - At the end of the day, we are transferring heat from the air into the water, meaning the efficiency is capped by the need to replenish heat "lost" to heating water. In other words, no free lunch, unless you live in a warm climate where the unit can be located in a garage or outside the occupied building envelope.
    For background and follow-up, we're in Kentucky and the unit was located in the 2500sqft open basement. Noise was not an issue. Returned and replaced heat pump with traditional electric unit on candid advice of tech..

    1. mercifullyfree | | #22

      As a follow-up, 40 years ago I installed a Florida brand water source heat pump in South Carolina with an auxiliary unit that pre-heated water for the hot water heater. Back then I diverted water from the well and fed it to the garden after passing through the heat pump.

  9. drcruise | | #14

    My work takes me to New Zealand periodically and that has given me an opportunity to admire Mitsubishi’s Ecodan air to water hot water heaters. They have been on the market in Asia (and more recently in the UK) for years. Mitsubishi is years ahead of many other companies in developing and improving their technology, and yet they haven’t introduced their residential units to the US market (they do have commercial equipment in the US). Has anyone heard anything about their imminent arrival to the US residential market? With 30% rebates, and an admired brand name, what could be keeping them out?

    1. efishinsea | | #16

      Drcruise, that is a great question! They would sell like hot cakes. I'm an energy consultant in MA. I get a LOT of inquiries why the big companies don't offer Air>water heatpumps. And of course split HPWHeaters .

    2. charliepark | | #17

      I can't speak to Mitsubishi, but the Ecodan looks similar to the SANCO2 air-source hot water heater — — which is available in the US through certain distributors. It seems like a great system!

      1. drcruise | | #19

        True, but the residential Ecodan does not use CO2 (yet), the Sanco does, and there’s presently a hitch with CO2 as a refrigerant… it operates at a much higher pressure so the lines & fittings are built to a different spec. Testing & commissioning requires additional training & metering. Commercial outfits may be familiar with the setup (since some larger grocery chains and refrigerated warehouses are beginning to adopt CO2) but most residential HVAC guys won’t be familiar (yet). Having been out on the bleeding edge a few times, I’m not ready to go back out there. I’m in Santa Fe and the nearest Sanco distributor is in Denver (6hrs). Here there’s one contractor that did a Sanco installation on a trial basis. If you want Sanco and service, you might need to go to Australia.

    3. nickdefabrizio | | #18

      I have seen ads for these units as if they are here and yet you cannot find them in retail in the US! Can't wait.....

  10. bradrea | | #20

    Hello Jon,
    After reading your 27 January 2023 article in the Green Building Advisor on the newly configured and improved State Premier AL Hybrid Electric water heater I was impressed enough to try and research that product further. Aside from your article and its imbedded drawing which clearly illustrates the highly desirable top-side inlet and outlet air-venting configuration of the State Premier AL water heater, I was not able to find any other online reference to the revised State Premier AL Hybrid Electric product upgrades. It seems that neither State nor AO Smith have updated their promotional brochures and online reference information to reflect the newest configuration of their hybrid water heater products. When I phoned the listed Customer Service number on the State website, I was switched to an AO Smith customer service operator who knew less about water heaters than I do.
    Do you happen to know if the new modifications which your article describes pertain to both State Premier and AO Smith Voltex Hybrid Water Heaters? I ask that because none of the online brochures and reference documents which I was able to locate illustrate the top-side inlet and outlet air-venting as is clearly shown in the drawing which you provided. Thus, without finding "official" information from AO Smith and/or State, nor without being able to contact knowledgeable customer service personnel, I have no idea how to make any further inquiries regarding the State Premier AL Hybrid Electric water heater that your article describes.
    Are you able to post additional contact information for knowledgeable personnel at either AO Smith or State.
    Much thanks,
    Brad Rea

    1. bradrea | | #21

      OK, although I had to dig a bit, I was able to locate AO Smith literature which clearly illustrates the "top-side" inlet and outlet air venting that I find to be a very convenient design modification. I did not find that type of literature for State HPWHs, but thankfully, AO Smith has updated their literature very much to my satisfaction.
      Brad Rea

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