Is it time to replace an old inefficient water heater? Inefficient water heating systems make it difficult to provide enough hot water for the usage of your family and cause energy bills to soar. Like most homeowners, you’d probably like to feel comfortable with your hot water heating system without breaking the bank. Because water heating amounts to nearly 20 percent of a home’s energy costs (according to Energy.gov), it’s important to get a new water heater which has a high energy efficiency rating. Heat pump (Hybrid) water heaters are the most efficient tank water heaters on the market, they can be two to three times more energy efficient than conventional gas or electric resistance water heaters. They’re the best options to invest if you want to save money in the long run. Our buying guide shows you what to look for when buying a new heat pump water heater, including unbiased expert reviews of the top-rated heat pump water heaters on the market.
If you just want to see our recommended model reviews then just skip the first half of the article, but for your convenience, we’ll list our picks for the best heat pump water heaters:
- Rheem Prestige Series Hybrid Heat Pump Water Heater 80-Gallon
- AO Smith Voltex Residential 80-gallon
- GE GeoSpring 80-gallon
- Stiebel Eltron Accelera E 58-gallon
Note: We think 80-gallon is an optimal size to satisfy average annual household hot water demand as much as possible via the heat pump.
What Is a Heat Pump Water Heater – How It Works?
Heat pump water heaters are a relatively new type of water heater that extracts heat from air and transfers that energy to heat water in a tank. They use the same technology as refrigerators or air conditioners but in reverse. While a refrigerator removes heat from an enclosed box and expels that heat to the surrounding air, a heat pump water heater takes the heat from surrounding air and transfers it to water in an enclosed tank. It heats a water tank with a remarkable efficiency.
To help you understand how a heat pump water heater works, we briefly summarized the main points. In operation, a fan mounted on the top of a water tank pushes room air across a radiator-like grid filled with cold liquid refrigerant in a closed system of tubing. The refrigerant has a low boiling point, and the air’s heat raises the liquid’s temperature enough to turn it to a gas. An air compressor then increases the pressure of the gas, further raising its temperature. A pump circulates the tubes filled with hot compressed gas down and around the cool water in the heater’s tank. The heat from the hot compressed gas moves toward the cool water, raising its temperature and cooling the gas back to a liquid where it is then pumped back to the radiator, and the fun starts again.
When emptied, heat pump water heaters take longer than conventional electric water heater to reheat to have you back in hot water. Why? Because heat pumps draw less electricity than an electric water heater for more energy efficient. So when buying a new heat pump water heater, you should consider a larger tank capacity to ensure you have enough hot water when you need it. Most models have backup resistance elements. During periods of high hot water demand, they switch to standard electric resistance heat automatically – they are often referred to as “hybrid” hot water heaters.
One of the most important things you should know before getting a heat pump water heater is that this water heating system doesn’t work well in very cold spaces and need to be placed in an area that stays 40 to 90 degrees F (4.4º–32.2ºC). And because the heat pump captures heat from the air, you need to provide at least 1,000 cubic feet (28.3 cubic meters) of air space around the water heater.
Heat Pump VS Electric
Even though all the hybrid heat pump water heaters are more efficient than conventional electric water heaters. That doesn’t mean you’ll find them the most cost effective for your family. So before you plunk down big bucks for a heat pump water heater, take a minute to understand why it’s better than a conventional electric water heater. Your goal is to find the right balance between performance and efficiency for your particular home.
Heat pump water heaters use electricity to capture heat from the air and transfer it to the water instead of generating heat directly. Therefore, they can be two to three times more energy efficient than conventional electric resistance water heaters. A heat pump water heater can save a household of 3 up to $240 per year on its electric bills compared to a standard electric water heater and over $2,380 over the water heater’s lifetime. Larger families typically use more hot water then they will save even more!
The main disadvantage of a heat pump water heater is its slow recovery rate. Recovery rate is the amount of hot water the water heater is capable of providing in a given period of time. Recovery rate is based on gallons per hour (GPH). A typical heat pump water heater has a recovery rate of eight gallons per hour (GPH = 8). Meaning that once the tank has been depleted you could be waiting for up to 7 hours until it can recover and provide a full tank of hot water again. A 50-gallon typical electric water heater has a recovery rate of 23 gallons per hour (GPH = 23) so it will take approximately 2 to 3 hours to provide a full tank of hot water again.
- If you’re looking for a 50-gallon tank water heater, click to read our reviews and buying guide
Cost and Lifespan
Heat pump water heaters typically have higher initial costs than conventional electric units. A new 50-gallon hybrid heat pump water heater will cost you around $1,500 and an 80-gallon unit will probably cost over $2,000. It depends on which brand you purchase. With electric water heater, you can get a 50-gallon unit at less than $800 and an 80-gallon unit at less than $1,200. While initial costs are higher than most other electric water heaters, heat pump water heaters have a longer lifespan and would be much cheaper to run.
Heat Pump VS Gas
Electric heat pump water heaters are much more energy efficient than gas units. In contrast, gas water heaters provide a higher level of comfort because it has a faster recovery rate. Another advantage of gas water heaters is that they’ll still work in the event of a power outage.
To help you understand why heat pump is much more efficient than gas, we’ll talk about Energy Factor. Energy Factor (EF) is a measurement that’s used to describe the energy-efficiency of a water heater. It’s based on the amount of hot water produced per unit of fuel consumed over a typical day. The higher the energy factor, the more efficient the water heater.
Most typical gas water heaters have an EF of 0.57 to 0.62. Some manufacturers make models that are better insulated, and have ratings as high as about 0.7 (such as the A.O. Smith GPVL-50 ProMax Power Vent – read our reviews here) – which would contribute to maybe $30 to $40 in annual gas savings. Consider the heat pump water heaters, most of them reach an EF of 2.86 or above. However, the lower EF doesn’t mean a gas unit will cost more to run. Because one of the problems with comparing the cost of operating a gas water heater to an electric heat pump water heater is that you’re billed for each in different units. You pay the gas company for how many therms you use and the electric utility for kWh. If you really want to know which is cheaper, you’ve got to do the conversions and find out the estimated annual cost of operation for each fuel. Use the following calculations:
365 X Btu ÷ EF X Fuel Cost (Btu) = estimated annual cost of operation
1 therm = 100,000 Btu
For heat pump:
365 x kWh/day ÷ EF x Fuel Cost ($/kWh) = annual cost of operation
The simplest way to estimate the annual operating cost of a water heater is looking at its Energy Guide label.
A gas water heater can heat a 50-gallon tank in about one hour. Its recovery rate is much faster than that of a heat pump unit. A typical gas unit will have recovery rates in the range of 40-gallon per hour (GPH = 40), there are heavy duty models that go as high as 50 to 60 GPH. So for families of four or more people, a gas unit is usually the better choice over the heat pump unit. However, if a heat pump water heater is your choice, you should consider a larger tank capacity to ensure you have enough hot water. An 80-gallon HPWT is the best option if your family has 3-4 people.
Cost and Lifespan
Gas heaters are much cheaper than heat pumps in initial purchase price. Installation of a gas water heater can be much cheaper if a gas line is already available in a house. An electric heat pump water heater will require you have a 220V outlet that will take you more money if you live in a 110V country. Heat pump heaters may have a slightly longer lifespan than gas units, but this largely depends on local water quality and maintenance.
Heat Pump VS Tankless (On-Demand water heater)
Before we move onto our in-depth reviews of the best heat pump water heaters on the market, we just want to make sure you know the difference between the heat pump and tankless water heaters.
Compared to the conventional electric water heaters, tankless water heaters are 27% to 50% more efficient. So tankless units are hard to beat heat pump units in terms of energy saving. Because heat pump units can be 2-3 times more efficient than electric units. However, because tankless water heaters don’t use a storage tank, they don’t produce the standby energy losses associated with storage water heaters, which can save you money.
Tankless water heater’s recovery rate is determined by the water flow per minute or gallon per minute (GPM). Typically, a tankless unit provides hot water at a rate of 1.2 to 6 gallons (1.2 to 6 GPM) per minute. A low-flow shower head may use 2 gallons of hot water per minute. A sink may run 1.5 GPM through the faucet while doing dishes and a running bathtub may use 4 GPM. A typical single tankless water heater can’t handle all hot water needs if you do multiple things using hot water at the same time. To overcome this problem, you can install two or more tankless water heaters, connected in parallel for simultaneous demands of hot water. But you have to spend a lot more money.
Unlike tankless, a heat pump water heater uses a storage tank to store hot water. You don’t have to worry about getting enough hot water for the usage of multiple sources at the same time. Tankless water heaters are the best options for families that use 40 gallons or less of hot water each day.
Cost and Lifespan
There so many tankless water heaters on the market that cost less than $500. But we would highly recommend you buy models from Rheem or Rinnai such as Rinnai RUR98iN 9.8 GPM or Rheem RTGH-95DVLN 9.5 GPM. These units may cost you a lot more but they are the best tankless water heaters available.
Tankless water heaters will typically last longer than heat pump water heaters. Most tankless water heaters have a life expectancy of more than 20 years. They also have easily replaceable parts that extend their life by many more years.
Choosing the Best Heat Pump (Hybrid) Water Heater
When selecting a new heat pump water heater, there are many things you’ll need to take into account.
What size do you need?
To properly size a heat pump water heater for your home, use the water heater’s first-hour rating. The first-hour rating shows how much hot water the unit can provide in one hour (starting with a tank full of hot water). It depends on the tank capacity and which model you purchase. You can see water heater’s first-hour rating on the top left corner of the Energy Guide label.
The first-hour rating primarily depends on your family peak’s usage period. Assuming a people shower in 8 minutes will consume 15 gallons of hot water. If your family has 4 people and all take their showers at the same time, you would need a heat pump water heater with at least 60 gallons first-hour rating. For dishwashers, clothes washers and other such applications that need hot water, you might want your water heater that has a first-hour rating of 90 gallons or above.
Use the worksheet below to estimate your maximum usage of hot water during this one hour of the day – this is your peak hour demand.
Water heaters are the second highest source of energy usage in the home. An ENERGY STAR certified heat pump water heater can be much more energy efficient than models without that certificate by heating water using highly efficient heat pump technology. And you can save even more with rebates. With an Energy Star qualified heat pump water heater, you can get a rebate up to $500.
To qualify for a tax rebate, ENERGY STAR hybrid heat pump water heaters 55 gallons and under must have an Energy Factor (EF) of 2.0 or above. ENERGY STAR hybrid heat pump water heaters over 55 gallons must have an EF of 2.2 or above. All Energy Star models in this review are eligible for a tax rebate. To determine whether there are rebates available for ENERGY STAR certified water heaters in your zip code, click here to find.
Where will your heat pump water heater be installed?
Your heat pump water heater should be placed in an area that stays 40 to 90 degrees F (4.4º–32.2ºC) with at least 1,000 cubic feet of air space around the water heater. They generally don’t work well in colder spaces and can cool the spaces they are in. If possible, consider installing in a space with excess heat, such as a furnace room.
BEST HYBRID HEAT PUMP WATER HEATER REVIEWS
1. Rheem Prestige Series Hybrid Heat Pump Water Heater 80 Gallon – Editors’ Choice
- Energy Factor: 3.55
- Energy Use: 1255 kWh/year (a standard electric water heater consumes more than 4,500 kWh/year)
- Warranty: 10-year warranty for tank & parts
- Work with Nest: yes
- Rebates & Incentives: Yes
When it comes to the heat pump water heating system, everyone talks about Rheem. The Rheem Prestige Series is the best hybrid heat pump water heater currently available. It’s the most efficient unit on the market, making it easy to help homeowners save an estimated $4,000 in energy costs over 10 years. This model is compatible with all applications you need, especially where space or climate is an issue. It features easy access to your home Wi-Fi network and can be controlled via a mobile app, allowing for customizable temperature, vacation settings, energy savings and system monitoring at home or away. If you’re looking for a highly efficient water heating solution that costs less than 60¢ per day to operate and is packed with modern features, we recommend this Rheem model.
The Rheem Prestige Series delivers hot water faster than most conventional electric water heaters. A 50-gallon model delivers 67 gallons of first-hour rating, a 65-gallon model delivers 75 gallons of first-hour rating and an 80-gallon model delivers 89 gallons of first-hour rating. You have 3 options to choose depending on your home usage. If your family has 3 to 4 people, we recommend you buy an 80-gallon model. Smaller than that may be not enough hot water to supply if some applications are used simultaneously.
This model has an amazing 3.5 Energy Factor – which is the highest rating compared to any other heat pump water heater we reviewed. As it’s super energy efficient, it will save you a lot of money in the long term and will pay for itself in less than 4 years.
Rheem claims that this model is the smartest water heater on the market. We don’t think so, we think it can’t be smarter than the GE GeoSpring (listed below). It uses the EcoNet WiFi-connected technology and a free mobile app that gives users control over water systems, allowing for customizable temperature, vacation settings, energy savings and system monitoring at home or away. It’s also compatible with Nest Thermostat – a smart home device which helps you save more energy. Nest Thermostat allows EcoNet to place your heat pump water heater in vacation mode while the Nest Protect detects smoke or carbon monoxide.
The Rheem Prestige Series also features an exclusive water leak detection sensor. This sensor detects water outside of the unit and sends an alert to your smart phone.
Rebates & Incentives
The Rheem Prestige Series heat pump water heater meets the latest Energy Star standards. We’ve found rebates for this product totaling up to $300. Click here to apply online for a rebate, download and complete the rebate form. Don’t forget you have to apply within 60 days of purchase.
2. AO Smith 80 Gallon Voltex Residential Hybrid Electric Heat Pump Water Heater Reviews
- Energy Factor: 3.24
- Energy Usage: 1884 kWh/year
- First-hour rating: 84 gallons
- Warranty: 6 years
- Rebates & Incentives: Yes
If our top pick doesn’t fit your needs, grab the Voltex Hybrid Electric heat pump water heater from A. O. Smith. With annual savings of $387 or more for the life of the appliance and A.O. Smith’s excellent customer services, there is no better way to go than this model.
The Voltex Hybrid reduces water heating cost by up to 66% through an innovative design that pulls environmental heat while dehumidifying and cooling the ambient air at the same time. The 80-gallon tank enables you to maximize your savings by generating heat through the heat pump technology instead of the heating elements. It also offers premium features like a user-friendly LCD display, vacation mode, and a powered anode that protects your tank for 6 years.
This model is one of the quietest heat pump water heaters on the market, operating at just 51 decibels. It features four operating modes that maximize efficiency by matching heating requirements to environmental conditions. Hybrid mode automatically adjusts between compressor and element, depending upon heat requirements. Vacation mode reduces operating costs and provides freeze protection during the extended absence, this mode can be programmed up to 99 days.
Rebates & Incentives
This is an Energy Star qualified water heater so it will qualify for the existing federal energy efficiency tax rebate and most state and local utility rebates. You can get a rebate up to $300 for this model. Click here to for more information. Don’t forget you have to apply within 60 days of purchase.
3. GE GeoSpring Heat Pump Water Heater (80-gallon) Reviews
- Energy Factor: 3.25
- Energy Usage: 1407 kWh/year for 80-gallon units
- First-hour Rating: 69 gallons/50-gallon unit and 94 gallons/80-gallon unit.
- Warranty: 10 years
- Rebates & Incentives: Yes
We’ve discovered that we can get a GE GeoSpring or Rheem Prestige Series heat pump water heater for the same price and rebates. They are both smart and the most efficient hybrid heat pump water heaters on the market. So, which is the better one?
The GeoSpring electric heat pump water heater is one of the first residential electric water heaters with an electronic back-lit LCD display. With 4 modes and a vacation setting to choose from, you can start maximizing your energy savings immediately. Heat pump mode is the most efficient mode providing you with the greatest amount of savings. Hybrid mode provides you with a faster recovery time than the heat pump mode. High demand mode allows the unit operates similar to hybrid mode, but with a faster recovery period. Standard electric mode is designed for extremely cold ambient temperatures under 35 degrees F, where heat pump water heater doesn’t work well.
The best feature of the GE GeoSpring is that it can be controlled via GE Wi-Fi Connect. Like some smart air conditioners with an add-on device which allows you to control the unit from your smartphones, you can use the GE Wi-Fi connect module (purchased separately) to monitor your water heater using the GeoSpring app. Furthermore, it works with Amazon’s Alexa, so you can control the unit via voice commands. This heat pump water heater is also relatively quiet. Its sound is similar to the hum of a microwave vent fan.
Rebates & Incentives
GeoSpring heat pump water heaters qualify for many state tax credits and utility rebate programs. You can get a rebate up to $300, click here to apply online. Don’t forget you have to apply within 60 days of purchase and you must be a PG&E electric customer.
4. Stiebel Eltron Accelera E Heat Pump Water Heaters, 58 Gallons
- Energy Factor: 3.05
- Energy Usage: 1,040 kWh/year
- First-hour Rating: 51 gallons
- Warranty: 10 years
- Rebates & Incentives: Yes
You may not be familiar with the Stiebel Eltron brand. Stiebel Eltron is a company based in Holzminden, Germany that was founded in 1924 by Dr. Theodor Stiebel to manufacture his revolutionary immersion water heaters. More than 90 years later, the company is still family owned and is a household name in Europe, known for the engineering and manufacturing excellence of tankless electric water heaters, solar thermal equipment, heat pump water heaters and more. Stiebel Eltron heat pump water heaters are the best choices for those who are looking for an energy efficient water heating solution.
The Stiebel Eltron Accelera E Heat Pump Water Heaters is 100% heat pump – not hybrid. In cases of high demand, one specially-designed electric “booster” element is located at the very top of the tank. Positioned near the hot water draw point, the element has been designed and engineered to run as little as possible. With just one efficient setting like that, you do not have to worry about adjusting various controls to balance both comfort and savings. Its super-insulated tank keeps water hot up to 2-week for less than $4.
Because heat pump water heater’s recovery time is slower than a standard tank, this 58-gallon water heater is ideal for a small home (3 people or less). Similarly, the Accelera 300E tank is 80 gallons because it is an optimal size for larger households.
Rebates & Incentives
Accelera 220E heat pump water heaters are Energy Star certified. We’ve found there are a number of local government and utility rebates available across the country that the Accelera 220E qualifies for. A good place to look for rebates by region is The US Department of Energy’s Database of State Incentives for Renewables & Efficiency website, DSIRE.