Model # Accelera 300

Internet #203899071

Stiebel Eltron Accelera 300 80 Gal. Tall Hybrid Heat Pump Water Heater

Discontinued Stiebel Eltron

Accelera 300 80 Gal. Tall Hybrid Heat Pump Water Heater

  • First hour rating is 78.6 gal.
  • Superior insulation guarantees ultra-low standby losses
  • Same-day installation in most areas. Call 1-855-400-2552 by noon.

Frequently Bought Together

Product Overview

Stiebel Eltron developed tankless electric water heating technology 90 years ago and continues as the industry pioneer and world leader. Our engineering excellence and high-quality manufacturing results in products fulfilling the highest expectations of performance and reliability. Thirty years of heat pump experience have taught us how to design a heat pump water heater to be as efficient as possible. The Accelera 300 extracts 80% of the heat it needs to make hot water from the energy in ambient air. We rely on the heat pump to make hot water, not on the back-up element. Heat pump draws only 500-Watt and every watt it uses generates 3 - 5-Watt of hot water. Over a year our 80 Gal. tank is more efficient than competing 50 Gal. tanks. In warm climates, the unit can be placed in a garage, where it uses the heat from the outside air; or inside the house, where it helps with air conditioning. In cooler climates, it is typically placed in a basement where it also dehumidifies the basement. Heat pump water heaters are not a new concept in Europe, and the Accelera 300, engineered and made by us in Germany, has been the largest seller there for 30 years. The Accelera 300’s ENERGY STAR energy factor is 2.51, the highest in the category.

  • Accelera 300 qualifies for federal, state, local, and utility financial incentives that may be available for heat pump water heaters
  • Single, specially-designed 1700-Watt back-up element can be disabled
  • 80 Gal. (300 l) tank is designed so 50 Gal. of hot water can be drawn before the back-up element is needed
  • Only wrap-around aluminum condenser on the market means no possible contamination of potable water
  • Glass-lined tank resists lime for longer life and the anode rod is replaceable
  • Can be powered by photovoltaic array
  • Higher the ambient air temperature where the unit is located, the greater the efficiency will be
  • Heat pump requires sufficient air in order to work and should not be installed in a closed space smaller than 10 ft. x 10 ft. x 8 ft.
  • Water heater height is approximately 75 in. tall and 1 ft. minimum additional is needed for servicing
  • Heat pump will dehumidify the space where it is installed and cool it down approximately 2-6°F (1-3°C)
  • Moisture removed from the air by the heat pump will require a condensate drain
  • Make sure the floor will support 1000 lbs., the weight of a unit filled with water
  • Do not install in a location where air temperature regularly drops below 42°F (6°C) or above 108°F (42°C)
  • All heat pump water heaters make noise roughly equivalent to a freezer while in operation and should not be installed where this would be a problem
  • Click here to check out our buying guide on water heaters
  • Inlet and outlet fittings are 1 in. NPT; condensate drain and T and P fittings are 3/4 in. NPT
  • Click here for more information on Electronic Recycling Programs

Info & Guides

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Warranty / Certifications

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Customer Questions & Answers

Average percentage savings over conventional 220 V 80 gal tank?

I need to know a return on investment to see how long it would take (on average) to justify the additional cost.
Asked by: Anonymous
My friend said she saved about $40 a month once she was using the heat pump water heater. When it was off for service, then the electric bill went up $40.
Answered by: GoldenHVAC
Date published: 2016-01-29

Does warranty require professional installation?

Some product manufacturers require professional installation for their warranty to be valid. Is that the case with this unit?
Asked by: RJ
If the install is simple and you are an accomplished DIYer I would say yes. But we had some more compicated plumbing to do and changing of electrical, so I opted for professionals.
Answered by: papalion
Date published: 2016-01-15

What size house is this appropriate for ?

2-4 people, 3-5 people, 4-6 people 2-4 bathrooms, 3-5 bathrooms, etc ??
Asked by: chachi
This has a 80 gallon 'First hour' rating, meaning that with the tank full at 120F you can draw out 80 gallons of water that will be over 105F. This should be good for 2-4 bathrooms, and 6-8 people. Of course if they are all college students taking a shower at 6 am, you might run into a problem. If they take showers more than 30 minutes apart, then no problem recovering between showers. Recovery should be about 24 gallons per hour in the heat pump only mode. GE is building a higher capacity 'Norther Climate' HPWH that is rated to run in heat pump mode while in a 37F room (below 37 it changes to electric only mode) and is rated at 4 showers before reaching 105F. This is defined as 2 GPM draw for 8 minutes, then 5 minutes no draw, then 2 GPM X * minutes, 5 minute break until the water temp going out is less than 105F. The GE 80 gallon HPWH was able to draw out 4 times before reaching 105F. If you need a LOT of hot water, then the Nyle CCHP Cold Climate Heat Pump is rated at many more gallons per minute, and designed to be mounted outside, with 0F ambient, it can produce many gallons of hot water each hour. It uses a 24,000 Btu compressor. This water heater uses a compressor rated at roughly 6,000 Btu's per hour. It also is about as noisy as a microwave.
Answered by: GoldenHVAC
Date published: 2015-12-28

Can a whole house hot water recirculating pump be connected to this heater?

Asked by: Mike
Don't know, but there is no need to do it.
Answered by: papalion
Date published: 2016-09-23
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Customer Reviews

Accelera 300 80 Gal. Tall Hybrid Heat Pump Water Heater is rated 4.4 out of 5 by 19.
Rated 4 out of 5 by from some unique features Just a few cautions for an installer: All access to this HPWH is through the top. This is critical in basements with a 7-ft ceiling, but not an issue in newer basements with a 9-ft ceiling. The top cover has to be removed to make the wiring connections, and the two thermostats (one for the HP and one for the element) are accessed through the top. These are set independently, and the factory specifies that they should be set to the same temperature. There are no graduated temperature markings on the thermostat knobs, however. You might want to pre-install a junction box on the side of the tank with pigtail leads going to the junction box inside the tank. That way, you don't have to reach into the top of the tank to connect wires in a low-ceiling situation. Installing a bushing between the box and the tank wall is a challenge because of the foam insulation inside the tank.
Date published: 2014-01-28
Rated 5 out of 5 by from Water Heater Replacement Needed to replace an aging water heater, and tried an on-demand unit but it was hard to get the water temperature to stay consistent. Decided to go the extra $$$ for this model. It was delivered by truck to the curb at my house, and was well packaged in a wooden frame with abundant Styrofoam packing. It is a large unit and it needed to go in the basement, which was a bit of a challenge. But once there the hook-up was fairly simple and once filled with water and turned on we had hot water fairly quickly. I had to downgrade the circuit breaker from 30 to 15 amps. So far the unit has operated fairly quietly with a low amperage draw. Best part is we have no shortage of hot water!
Date published: 2015-03-25
Rated 5 out of 5 by from excellent product Had it professionally installed. Installer enjoyed the quirkiness of a german designed product in regards to fittings, but came to the conclusion, that it is superior than any other currently available hybrid O2 heater on the market. Took about 3 hours to install. Produced hot water immediately and has not stopped since. (about a month now) Electric bill is about 30% lower. Beautiful design, clean forms and it cools my garage now very nicely! It took about 30 minutes to just get it out of its packing. No louder than our refrigerator that stands next to it in the garage. Overall highly recommended.
Date published: 2015-06-26
Rated 5 out of 5 by from Great Waterheater We had an old 25 gal. water heater connected to our furnace. Therefore the furnace had to run even in the summer only for the water heater. Now I replaced it with the Stiebel-Eltron ACCELERA 300. It requires a 220V power connection. The Unit came crated on a pallet. Over 6 ft tall. It's huge and definitely not easy to move by one person. But it is possible. Installation was relatively easy. The strange thing is that the front side has all the Cold and hot water connection while the back side is sleek. I use the back as the front side and have all connection in the back. It looks better but the built in fan from the Heat Pump blows out on the back side. Because I use it the other way around, the fan blows into the room. After starting the unit, it took only approx. 30 min. until the water was warm enough for a shower. You definitely will feel the cooler room temperature after a few hours and yes, the Heat Pump compressor is a little bit noisy but not too much. It is a little bit louder than our Heat Furnace. The Heat Pump technology is great. And due to the fact that it works also as a dehumidifier it's great in the summer. Especially when the unit is installed in an area where no AC is installed. So far, so great.
Date published: 2014-01-20
Rated 5 out of 5 by from German engineering in a water heater, top notch efficiency This is about the most efficient water heater money can buy. The break-even point on your investment of $2k+ is only about 3 years compared to electric. If you're replacing an existing 240VAC water heater, this install is a snap, with the only difficulty being the unit's size and weight. It's almost 6ft tall and weighs 290 lbs. If you have decent access to its final destination and 4 strong guys, it's no big deal and only an hour worth of grunting and straining. If you're not replacing an existing electric water heater (I wasn't), it's still not that big a deal, just a bit more plumbing. I'm a DIYer, not a pro plumber or electrician, and I did it in one day. [but I do know how to run copper pipe and wire 240 outlets] It's not that loud and heats 80 gal of water very efficiently. what more could you ask? Time will tell on the reliability, but I'm thinking the German engineering will prove to be worth it. Thumbs up all around. Get one now.
Date published: 2015-02-10
Rated 5 out of 5 by from Solar panel equivalent Let's put it this way, using this water heater instead of my old water heater is the equivalent of adding 6 solar panels to my roof.
Date published: 2015-09-01
Rated 5 out of 5 by from An excellent piece of equipment I installed one of these in front of our Tempra 24 Plus to use during the summer months, and in case of a power outage. The Tempra 24 is an efficient tankless unit-- however, in comparison the heat pump unit is effectively free to run during the cooling season. I say "free to run" because this unit removes heat from the house that would normally have to be removed by the air conditioning. It also takes some of the strain off of our dehumidifier, as it cools and dehumidifies the air as it runs. In a two-person household, it lowered our electric bill approximately $40 per month. It is worth noting that everything in the house is low water usage-- from the shower heads to the washing machine to the dishwasher. I was a bit apprehensive going back to a tanked unit, as we've had poor results with previous tanked water heaters with regard to temperature regulation. I'm pleased to report this unit keeps the temperature within +/-2 degrees Fahrenheit of the set point. Our previous tanked water heaters would vary +/-5 degrees Fahrenheit or more. The tankless unit has spoiled us with its ability to produce water at exactly the temperature set point, but this heat pump unit is a very close second in its ability to maintain a steady, reliable temperature. I neglected to time how long it took to raise the temperature from cold to the set point (114 degrees F) when it was put into service, but I would estimate that it was approximately 5 hours. It's worth noting that we turned the backup element off, and the unit is running solely on the heat pump. Recovery time may be an issue if you have a big family or are filling a large tub, as the backup element is quite small. However, due to the large capacity of the unit, we have yet to run out of hot water even with multiple long showers, laundry, and the dishwasher running simultaneously. Upon purchasing the unit, I was made aware by the factory that it does make noise, unlike a traditional water heater. I would put the noise level somewhere between a refrigerator and a quiet dehumidifier. Unfortunately, I do not have a decibel meter handy. The unit is in our laundry room in our basement, and we cannot hear it over normal background noise in our house. Some things to be aware of... This is a VERY large and VERY heavy unit. Before the unit is filled with water, it is extremely top-heavy and cumbersome to move around. If you are planning on installing this unit in a basement, be sure to enlist the help of at least two strong people and a heavy-duty appliance dolly, as it weighs about 300 pounds (and, again, is extremely top-heavy). Be sure to purchase and plumb a means to drain the tank; unlike a traditional unit, it is not built with provisions to do so. Due to the very modest power requirements of this unit, you will need to switch out the existing breaker for your water tank to a 2-pole 15A breaker. The unit is also very tall (at 6'4"), and all access to the heat pump, electrical connections, and thermostats is through the top. It is possible to install the unit in a 7' basement, but you should plan ahead to make use of the space between the floor joists to facilitate access to these things. This unit produces condensate while running, so you will need to have some means to drain it-- whether through the use of a pump, floor drain, etc. Since this unit removes heat from the room it's in, Stiebel recommends that it be placed in a room that is no less than 10x10x8. Of all the units I've researched, this is the only one where the refrigerant loop does not interact directly with the water in any way. The high pressure part of the loop (hot side) wraps around the outside of the tank, whereas in other units it is either immersed in the tank or in its own small reservoir with a pump moving water across it. The entire tank is insulated very well with closed-cell foam. In the future I will conduct a test to see if it loses enough heat during the day to start the heat pump running. With our usage, it runs twice a day for less than an hour each time-- only after a major water demand. All things considered, I couldn't be more pleased with this unit and its performance, and I would recommend it to anyone. EDIT: I timed the recovery of the tank from various temperatures and the results are: from 40F incoming water to 125F ~65F ambient air temp 7.5 hours from 50F incoming water to 125F ~75 ambient air temp 5.5 hours Again, these times are heat pump only as I disabled the backup element. The hot water was completely exhausted with no residual heat remaining for both of these tests.
Date published: 2015-04-21
Rated 5 out of 5 by from High Quality; but Needs Handles This is a great quality hot water heater, extraordinarily efficient. Home depot should keep these in all of their stores. All of that said, like many water heaters this one is perfectly round, top heavy due to it's design, and large; this combination makes for one very difficult to move appliance. Stiebel Eltron should definitely address this! We will be installing lots of these in the future!
Date published: 2013-05-28
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