Asked on Mar 18, 2012

Hybrid Heat pump Water Heater

Dawn C
by Dawn C
I've been lurking these boards for 6 months while doing a rehab of a 1918 house in Grant Park Atlanta, GA. I've been getting invaluable advice but NOW I'm stuck and need to ask for help.
8 months ago my husband and I decided on a Hybrid Heat pump water heater and the price has DRASTICALLY droppedin the last 6 months to only 1K-1150 dependent upon where you shop. I can't do tankless becuase of the cost of City of Atlanta Water and having to wait 3-4 minutes to get hot water - house is two stories, 4,500 sq ft, right now there are only 2 of us, we are building to plan for at least 2 kids, all bedrooms are upstairs, we are VERY energy efficient, and we aren't shower hogs. We will eventually put an insta/hot in crawlspace to get hot water to kitchen. We planned to put the water heater in the attic to make it most efficient, if you think that's a bad idea we do have a utility room we can use that's 900 Sq ft upstairs in hallway away from our bedroom
What I'm worried about is all the mixed reviews - what do the professionals really think about these things??
  17 answers
  • KMS Woodworks KMS Woodworks on Mar 19, 2012
    I do not have any "direct" experience with this type of heater but the science behind it is sound. As far as installing this in the attic that may be a bit of an engineering headache. 240 volt service + plumbing re-runs. These units like warmer surroundings as they "pull" the heat from around them to heat the insides. Having plumbing in the attic (and the unit which needs filter cleaning now and then) may contribute to more extensive damage if a leak should occur. Water as you know will follow gravity, a puddle in the basement is far less of an issue to deal with than a puddle overhead.

  • KMS brings up great points about service convenience and damage that can come from tank failure. Another thing to consider with the heat-pump water heater is that it puts out cold air whenever it is heating water. I like the concept of this technology but you need to take the cold air into consideration when you decide on the tanks placement.

  • Building Moxie Building Moxie on Mar 20, 2012
    I wonder if you are quickly ruling out the tankless system. with the heat pump I'd worry about structural reinforcement. tank failure could be mitigated to some degree. I like the efficiency behind double duty on a heat pump. if your plumber/HVAC feels good about it and your building department allows, I'd say you could do worse things. BUT I would not stop discussing other options with a plumber you trust.

  • Southeast Solar Co Southeast Solar Co on Mar 20, 2012
    1.The idea of installing water heater tanks in the attic is a bad one. Having lived through two time leaks installed by the previous owner on the second floor landing (caused considerable $$$$ damage) and switched it to the ground floor, I strongly suggest installing on the ground or basement floor. 2. I have read mixed reviews about the heat pump water heaters. As one of the above answers, consideration must be given to the exhausting cold air which can add additional burden and cost of heating the home during winter months. 3. Did you ever consider installing a simple solar thermal system. During the recent years the evacuated tube collectors which put out higher BTU even during winter months have become very popular. They cost as much as a good hybrid heat pump water heater. You also get federal and state tax credits bringing down the ROI. Besides by installing a simple water to air heat exchanger, you can additionally gain heat during winter months. Our own home in GA is heated by such a method and have saved $$$$.

  • Mark C Mark C on Mar 22, 2012
    Like you, I am always looking for ways to reduce energy use for our environment and my wallet! First issue, water heater in attic may not even meet code requirements. Due to the change in temperatures in non-climate controlled attics, plumbed devices are typically not in code compliance. For example, when I inquired about putting a furnace mounted humidifier on my attic unit, the city of Roswell, GA said "not in code compliance" due to plumbing into an unheated space. As for instant hot water heaters, I am not yet a fan. I like the idea, but with 3 full time adults taking showers in the am, I don't think that just one unit would work. Additionally, I use a gas fired conventional tank which is used both to heat our water and to heat a room in our house using the radiant floor heat setup. To avoid using too much water (while waiting for hot water to get to our upstairs showers), I installed a re-circulator with a timer on it (about $200 at Home Depot or less on line). I am using considerably less water, getting hot water instantly to all my upstairs water fixtures and helping to prolong the life of my water heater (the circulation helps keep the bottom of the tank free of sediment...number 1 cause of tank failure). While you are at it, if you don't already have attic foil installed beneath your roof, you may want to do it. Very inexpensive DIY project and it has already paid for about 50% of my cost in less than 6 months. Good luck!

  • KMS Woodworks KMS Woodworks on Mar 22, 2012
    good plumbing design can play a huge role in water delivery times. Not that my home was designed with that in mind...but it just happens to work out that way. Our master bath is located directly above the mechanical room where the water heater is located. The distance from the top of the water heater to the tub spout is less than 8 feet. When I turn on the tap hot water is there in 2 seconds or less. With a 3 valve rig ( hot cold divert) by the time I get the cold turned on every thing is right at temp and it is easy to dial in the right temp. When I design our retirement home this close proximity plan will be used again.

  • Scott H Scott H on Mar 22, 2012
    You might be interested in a recirculating pump to get hot water to your more remote faucets. There is a video of Plumbing and heating expert Richard Trethewey installing a recirculation pump to provide hot water quickly to a bathroom. You can see it here:

  • Ray Ray on Mar 22, 2012
    Dawn, I would not install a water heater in the attic, because of all the above reasons, I suggest a tankless heater with a on demand pump, you can activate with push button or motion sensor or stay with the hybrid heater and the demand pump or a Grundfos comfort series pump.

  • Plumbrite Plumbrite on Mar 22, 2012
    Dawn, I agree with Ray. I also charge more to replace heaters in attics, depending on access, and time of year. [already getting warm up there]

  • Dawn, It looks like everyone is not in favor of a tank heater in your attic. My clientele has chosen tank-less heaters almost exclusively. I have used one in my home for many years. . Ray's suggestion to install an on demand pump with it to eliminate wasted water is excellent. The pump will push the cold water out of the hot water pipe into the cold line until it reaches ninety eight degrees. A good pump will do this very quickly and efficiently. . A tank-less heater will provide you with an uninterrupted supply of hot water irregardless of how long you need hot water. They have proven to be very reliable for my clients, and easy to repair in the few times that required a fix. As I understand it, a tank-less heater can be rebuilt as necessary. This differs from tank heaters that ultimately rust out causing emergency service and damage to homes. . Tank-less heaters come in many varieties including direct vent models that can be installed within your home without burning the air within the home, or venting carbon monoxide into the interior.. . The water where I live is very hard. I wanted to avoid the risk of calcium build up in my heater and on my water fixtures. I chose to invest in a salt-less water treatment system that has worked very well for me for years. It has not only protected my tank-less heater, it has kept all of my faucets and shower-heads in beautiful conditions for years. I have seen many writers doubt the effectiveness of these units. Mine has served me well for years and I have not had any complaints from my clients that have followed my lead.

  • Building Moxie Building Moxie on Mar 23, 2012
    gotta say. really impressed with the breadth of knowledge that showed up on this thread. glad I commented if only to follow the thoughts that came after. happy Friday. good solutions Dawn. ~jb

  • Frank D Frank D on Mar 24, 2012
    Keep tank accessible for emergency water and gas shutoff. I have two 40gl in my attic and am not looking forward to replacing them. A neighbor of mine has his recirculate hooked to a motion detector in the master bath. It's set for 1-2min and so by the time he's done on the toilet he has hot water. Good luck! (What are you doing to upgrade the insulation?)

  • Southeast Solar Co Southeast Solar Co on Mar 25, 2012
    This is amazing. Everyone agrees on one thing. No tank in the attic. Did you consider installing a small solar thermal collector attached through a heat exchanger to a small tank (Say 40 or 50 gallon tank). This will keep plenty of hot water whenever you need. Secondly the cost of this entire system may be lesser than a tankless hot water system. Mike at Southface in Atlanta installed a system (He is the Director of technical services) a who can tell you a lot about such a system. ( Depending upon the size of such a system, one can use it to heat the home also.One of the chief architect from a vary large firm in Atlanta installed such a system in her home. She loves this as it is the most desirable bed room in her home. Overall this could save you almost 80% of your entire heating bill. This system can be hooked up to a solar thermal dehumidifier to offset your cooling costs and can make your home a whole lot more comfortable. There are tax credits associated with such an installation from federal and state.

  • Bret M Bret M on Apr 11, 2012
    I have been a remodeler for three decades. You need a rcirculating pump to keep hot water at the ready in the upsatirs units. No biggie, we do this every day. call me and I will handle it for you. visit our website @

  • Southeast Solar Co Southeast Solar Co on Apr 15, 2012
    Ron has been working with all phases of remodeling and has more than 25 years of experience. He is honest to a T and is very reasonable. He stands behind his work. You can reach him at Our company uses his service all the time. Mention our company name and he will help you.

  • Solar Energy USA Solar Energy USA on Aug 13, 2012
    Have you considered a solar thermal water heating system?

  • Mark Mark on Jul 14, 2016
    You can use a tankless water heater if you add an on-demand circulation pump like the WaterQuick Tankless system. It uses the cold water line to recirculate the water back to the water heater so you don't waste it. You will probably need their Premiere system because of the size of your house.