Best Heat Pump Water Heaters 2015

Following the entry of heat pumps into our lives in the last few years, water heaters equipped with this technology are becoming more and more popular every passing day. Instead of consuming electricity to produce heat, heat pumps use electric power to transfer the ambient heat from the air to the water tank in a way similar to the functioning of your fridge. That makes them extremely efficient in producing hot water and provided that you choose and utilize them correctly, their operation costs can be several times less than your old water heater.

A heat pump water heater is also called a hybrid water heater because all of them are equipped with auxiliary electric heating units. The electric heaters will switch on, only when the heat pump is not able to keep up with a sudden and heavy hot water demand and that is to make sure you do not have to take a cold shower. Thanks to the boost heaters they have, heat pump water heaters are reliable in providing hot water and can prove to be a great whole-house solution.

The information on this page was compiled to help you in your search for the best heat pump water heater. To do that, first of all, the features you need to check out when shopping for a hybrid is discussed. Next, unbiased reviews of the major brands that manufacture heat pump water heaters are provided. Having read through this page, you should feel sufficiently informed to make your own choice about the hybrid unit that will give you the best service and the lowest electric bills.

Finding the Best Heat Pump Water Heater

There are a number of features that tell us how efficient and effective a hybrid is in serving hot water to your faucet and shower. Let us now review these features.

Energy Factor: Energy factor for a water heater is the ratio of heat output to the energy input delivered to a device. Plain gas water heaters have an energy factor less than one because they waste some of the heat they produce. Hybrid heat pump water heaters have energy factors of two or more and that means they are two to three times more efficient than the most efficient tankless water heaters. Calculation of the energy factor is based on objective standards developed by the Department of Energy. This is great because it leaves little leeway for companies to lure customers with confusing data and provides a reliable tool for us to compare products.

What you need to remember is that energy factor may not always reflect the real-life energy saving potential of a heat pump. If there is a sudden surge in hot water demand like several people showering in close intervals, the unit can run out of hot water and its electric resistance heaters will be engaged to keep up with the hot water use. A small water tank that runs out of hot water quickly means more electric use and less savings.

Tank Size: Because heat pumps can take some time to heat the water, it is best that a large tank of hot water is kept ready to meet a suddenly surging demand. Most hybrid water heaters are either 50 gallons or 80 gallons. If you are single or a childless couple or there is no peak hour for hot water in your home, a 50 gallon tank should do fine. If you have at least two teenage kids and people flock to the showers in the morning etc. you will run out of water with a 50 gallon tank and you will start using electric power to get hot water. Plus, you may even experience periods of lukewarm water. In that case, do not underbuy and get the 80 gallon tank.

First Hour Rating: This is another objective DoE specified data about hybrid hot water tanks. It tells you how many gallons of hot water a fully heated water heater can deliver in one hour. It basically depends on the tank size, the power of heat pump and the power of the electric resistance heater.

This is how First Hour Rating is measured: Inlet water temperature is set at 40°F and the unit's thermostat is set to 135°F. Water heater starts with a full tank of water at 135°F. Water is drawn at 3 gallons per minute until temperature falls below 135°F. Water is drawn again once the water heater reaches 135°F. This goes on for an hour and the total amount of hot water that the unit was able to supply during the test gives us what we call the first hour rating.

First hour rating is a very useful piece of information to estimate whether a heat pump water heater will be able to keep up with your home's peak hour hot water needs. Do your calculation based on every faucet and average shower head taking two gallons of water per minute. Remember that 135°F is way too hot so you will probably be mixing cold with hot water so not all the water from the faucets will come from the tank. If not sure, here is the DoE page on Sizing a New Water Heater.

Expected Annual Energy Consumption: This factors in the energy factor, the tank size and everything to give you an estimation of how much electric power the device will devour per annum. I think this is the best piece of data to get an idea about how much money on bills you are going to save with a certain heat pump water heater. Department of Energy website has a page for every water heater heat pump in the market and that's where I take the data so we've got another piece of reliable, unbiased information to compare various models in the market.

HP50RH Rheem Heat Pump Water Heater

Rheem released the first residential hybrid water heater years ago and despite some cosmetic improvements, no ground-breaking changes have been over the first model. Presently, I am not sure if it would be right to call this the best heat pump water heater but there is good reason to think that it is one of the noisiest out there.

energy factor:
tank capacity:
50 gal
first hour rating:
57 gal
annual energy consumption:
1792 kWh
noise level:

Whether they like this hybrid water heater or not, the first thing you will probably hear from anyone who owns a Rheem heat pump is this: It's very laud! Even people who are perfectly happy with its service admit that the noise can be annoying. Others complain it can be heard from the garage and some customers even relay stories about the pipes in the whole house rattling because of the vibration. With no official data on the machine's decibel rating, many people compare it to a car engine, which has to be 70 dB at least and that makes it very noisy, indeed.

Product specs sheet says it can work in temperatures as low as 37 °F but in reality, it will function only as a plain electric water heater once you go below 50 °F, not as a heat pump.

In all other aspects, Rheem hyrid water heater looks OK. Energy factor is 2.45, which is what you would expect from any hybrid. In addition to the heat pump function, it's got two electric resistance heating units that are activated to support the supply of hot water, once the water temperature falls below a certain level. There are heat-pump-only or electric-heating-only modes. Some people complain the boost heaters take time to start heating and it results in a period of lukewarm water. That is expectable as this one has a relatively low first hour rating. If you have several family members who take shower at the same time of the day, this one may not be the most efficient choice.

If you believe that a Rheem unit would the right answer to your water heating needs, you should take note fo a few tips that will help you avoid common issues people have with these. First, you should make sure it is located in a place where the noise is not a problem. Next, using plastic piping or connectors instead of copper can curb the vibrations from the unit. Also, do not transport the unit lying on its side as that is reported to let the refrigerant leak around inside the unit and cause issues.

A.O. Smith PHPT-80

This is one of the big options for big families. Equipped with a 80 gallon tank and powerful boost heaters, PHPT-80 can supply up to 84 gallons of hot water in one hour and that's more than enough for an entire family to shower lavishly. Fulfilling as a water heater, it is not the top choice as a heat pump.

energy factor:
tank capacity:
80 gal
first hour rating:
84 gal
annual energy consumption:
1850 kWh
noise level:

Despite the expectation that a large storage tank will translate into better efficiency, PHPT-80 is far from being the most efficient heat pump water heater in the world. Its energy factor is 2.33, which although not terribly lower than its competitors, is one of the lowest in the hybrid market. A.O. Smith hybrid achieves its decent first hour rating by depending on the two electric heater units with 2000 watts and 4500 watts power. Not surprisingly, its annual energy intake is more than 450 kWh more than Stiebel Eltron's Accelera® 300, which has a similar size and a similar price.

As for the noise, no data is available but no complaints are reported either so we can assume an average noise level.

In short, A.O. Smith's 80-gallon hot water tank with heat pump is a solid unit that will not let you down when you need hot water. But it tends to solve the problems with resort to heavy use of electric power rather than efficiency. Your energy savings with this installed in your home, would not be comparable to what you can achieve if you had a Steibel Eltron heat pump that comes at a similar price. That's why I suggest you check out Stiebel Eltron Accelera® 300 reviewed below before you make your final decision.

GE GeoSpring™

While it is in no shape to be compared to the reputable Accelera® 300 by Steibel Eltron, the GeoSpring hybrid water heater manufactured by GE Appliances has a great price to performance ratio that forces me to grant it the "recommended" badge. I will also admit that I like the color.

energy factor:
tank capacity:
50 gal
first hour rating:
65 gal
annual energy consumption:
1830 kWh
noise level:
55 dB

The energy efficiency ratings of GeoSpring as seen in the table are what should be expected from a device at this size. It's got a 65 gallon first hour rating that is quite good for the tank capacity it has. That is achieved with the help of two 4,500 Watts electric heating units that get involved if the unit starts to run out of hot water. While that will be handy when you need a lot of hot water, you should remember that it will swell your bills.

One thing that makes GeoSpring hybrid water heater better than its peers is that it is probably the quietest heat pump water heater in the market. It works at only 55 dB and as expected, there are no complaints about it making any noise or vibrations like the Rheem. This is a product that could blend in with your residential spaces without causing your ears any discomfort although that does not mean you should place it in your bedroom.

While I often discourage the purchase of low price appliances, the primary reason I would recommend GE GeoSpring is the low price. I have seen it sold for as low as $1000 and if we are talking about a heat pump water heater, that's a steal. The good pricing coupled with the decent features I've mentioned above, makes GE Geospring an opportune choice for small households that want to try out the benefits of a hydrid unit but are not ready to invest in the ultimate heat pump.

Stiebel Eltron Accelera® 300

As of 2014, Accelera® 300 by Steibel Eltron is the ultimate hybrid heat pump water heater in the market. It is not only one of the newest products with state-of-the-art features but it is also the centerpiece of what Steibel Eltron has to offer as one of the leading water heater manufacturers in the world. Let us now see what makes Accelera stand out.

energy factor:
tank capacity:
80 gal
first hour rating:
76.2 gal
annual power consumption:
1391 kWh
noise level:
64.2 dB

First and foremost, Accelera® 300 is by far the most efficient hybrid water heater you will come across. With an unrivaled energy factor of 2.73, its expected annual energy consumption is a mere 1391 kwh per annum, which is 20 percent less than the closest competitor. Effective insulation of the tank and the powerful heat pump system contribute to the efficiency but of equal importance is the fact that Accelera® 300 was designed to depend more on the heat pump and less on the back-up electric heater. It's got a single electric heating unit located at the top of the tank, which is a quite weak unit when compared to the back-up heaters of other brands. Steibel Eltron goes so far as calling Accelera a true heat pump water heater rather than a hydrid. I think they are stretching but indeed Accelera is much closer to being a perfect heat pump and less close to being an electric water heater.

Steibel Eltron's heat pump has a 80 gallon tank and can deliver up to 76 gallon very hot water in an hour. That's slightly less than the above PHPT-80 by A.O.Smith but not to the extent to cause a concern. Accelera® 300 has more than enough capacity to support a family with kids at peak hour and does that with significantly less energy consumption.

As for the price, Accelera 300 is the most expensive hyrid in the market but not much more expensive than models that offer a lot less in quality and features. This is a high-end product from the most reliable water heater manufacturer and you can rest assured that you will be getting the best possible workmanship and service for your money. I recommend Steibel Eltron's Accelera 300 with no reservations.

Finally, I should remind you that it's quite a tall unit with a 90-inch height so before you buy this, make sure it is going to fit where you plan to place it.

Best Instant Hot Water Dispensers Prepare to drill another hole next to your sink, if you want hot water for cooking and you want it now. Hot water dispensers are for making life easier.

Best Gas Tankless Water Heaters Where propane or natural gas is available, tapping into these cheap and abundant sources of energy is a clever choice.

Best Electric Tankless Water Heaters : An electric tankless water heater can supply instant hot water for your home without bothering you with venting and gas connections. The reviews on this page should give you all the information you need on electric tankless water heaters.

Comments 7 comments

Chris 14 months ago

I need an 80 gallon electric heat pump water heater than can fit through my 25.25 basement door. I'd buy the steibel in a second except it can't fit into my basement. what would you recommend. geospring or something different at this point? I researched the ao smith and it is 700 more than the GE is it worth it.

bruce 13 months ago

Im looking into useing a heatpump water heater to heat my radiant heated home . Radiant slab , 2 zones . Running 110degrees through slab. 1500 sq ft home. Ive done it in a garage with a electric water heater before . Why wouldnt this work ?

tim 11 months ago

Bruce - not a good idea since the heat pump water heater extracts heat from the air and moisture around it. What you describe will in remove heat near the water heater, and move it to the others areas where the radiant slab is located. You in essence will end up heating with all electric heat since the heat pump will just steal heat that it is providing. I don't think your intent is to do all electric heating.

David 10 months ago

Will the Steibel work on a hot water return system?

Gina 3 months ago

These units should also cut our cooling costs as well, shouldn't they? We live in Florida and the air temp is 100 and with the dew point it feels like 110

Albi Fernandez 6 weeks ago

I am looking for Heat Pump Water Heater to supply 700 - 800 Liters of Hot water per day to be supplied to 20 Locations

scott 6 weeks ago

doesn't Rheem build the GE hot water heaters ?

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