Off topic: Residential Water Heaters

[Jethro3898]

I'm close to wrapping up the build on my new home (only took 15 months).
Getting ready to purchase a hot water heater and was looking for input from people with actual experience with the Electric Hybrid Water Heaters, specifically the Rheem units. Before any one starts typing, tankless isn't an option, nor is a gas powered tanked water heater an option either.
I am left with either a "traditional" electric water heater or a "hybrid electric" water heater.

There are so many people on these boards, that I would figure that there is a plumber or perhaps even a home owner who has experience with them.

Are the "hybrid" units worth the additional initial investment over the "traditional" electric water heaters? There is a relatively significant increase in price, but supposedly, within 3 years or so you bridge the gap simply with electricity savings.

The unit would be in my garage, so I have plenty of room (I read that they need sufficient air volume to pull from).
I also live in the deep South, so I have plenty of hot, ambient air for it to pull from and a relatively high inlet water temp.

Just looking for some real-world experience from some folks here who have dealt with the hybrid-electric water heaters.



Thanks.

 

[addertooth]

Air not required for electric. Not a concern. This is only an issue with gas heaters.
How hard is your water. That will determine whether a hybrid heater is appropriate.

 

[DarnYankeeUSMC]

I am pretty sure that he is talking about the heat pump type water heater. So air will be required to operate it.
The last one I looked at had a switching ability to change from the standard electric to the heat pump mode if the air temperature was going to be too hot or cold.
I don't have any personal experience with the heat pump model. But the guy that had it praised it pretty good. He's a contractor and everything in his personal house is high efficiency. His system was in the basement which is heated in the winter.

Air not required for electric. Not a concern. This is only an issue with gas heaters.
How hard is your water. That will determine whether a hybrid heater is appropriate.

 

[Jethro3898]

Yes....I apologize. I should have been more clear.
The Hybrid-Electric water heaters have a small heat pump on top of them (think refrigerator compressor, just in reverse). As DarnYankee pointed out, they also have a 4500 (or maybe it is a 5500) watt heating element like a traditional water heater. That's where they get the "hybrid" designation. They can run off 100% heat pump (super efficient) or 100% heating element (not efficient). Usually, they operate in "hybrid mode" where the heating element heats the water initially (i.e. quickly) and the heat pump then kicks in to maintain the temperature.

The people who use 100% heat pump mode have complained that it takes a long time for the water to get to temperature, which is why most people use it strictly in "hybrid" mode because it is the best of both worlds. I've read of people saying that they saved $450+ per year on their electrical bills once they switched from a traditional water heater to the hybrid-electric ones. $450 isn't a lot of money over the course of a whole year, but if you get 10-12 years out of the unit, like a normal water heater, you can actually see some decent savings.

All of that being said, for the heat pump to work, there has to be sufficient heat in the ambient air from it to pull from to heat the water (or perhaps better said, keep the water hot) with.....hence my original comment about the ambient air.

 

[Ravenworks]

Things that matter:
What is your water like are you going to condition it?
Buy from a plumbing supplier -vs- big box store if you're expecting quality.
Rheem is a great choice.
Flushing the heater regularly
Keeping an eye on the sacrificial A-rod, I changed mine every 3 years.

My first house I had bad water and would get a year or so out of a heating element.

I had good water at next home and got 16 years out of a Rheem doing due diligence on maintenance.

With good maintenance,water there is no reason for you to not get at least 10 years out of a unit

 

[ditter]

I'm in Miami and I have one in the garage. It's great. Very efficient. Got the Rheem from HD and had a plumber friend install. The cold air it exhausts is enough to cool the garage in the summer. Win-Win.

It's the future technology, so buy with confidence.

 

[frankxtc]

We are replacing our 15 year old AO Smith with a Bradford-White electric water heater.
(Made in USA!)
The AO Smith is still working fine, but it has to be near the end of life, and I never could get the **&^ electrode out of it so as to replace.
Looked at the Bradford-White heat pump version, but went with a normal heating element unit instead.
I don’t believe anything as complicated as a heat pump water heater will last anywhere near as long as a simple heating element type, so the projected savings might not actually materialize.
Since the kids grew up & moved out, we don’t use much hot water, thus not much savings on our electric bill in any case.

 

[greybeard]

Just recently read about a CO2 water heater, split concept with the compressor outside and only the tank inside, water pipe between.

Per reading, domestic hot water, at 175 degree requiring a tempering valve, + heating. Interesting reading.

 

[rjacobs]

I've read of people saying that they saved $450+ per year on their electrical bills once they switched from a traditional water heater to the hybrid-electric ones. $450 isn't a lot of money over the course of a whole year, but if you get 10-12 years out of the unit, like a normal water heater, you can actually see some decent savings.

I call HORSE SHIT on $450+ per year electric SAVINGS... I mean maybe in Cali where they pay 25c+ per KW... but in the south where electricity is relatively cheap...

I cant imagine my twin 55 gallon electric water heaters even cost that much per year combined to operate. No way they attribute almost $40 per month to my total bill.

I would guess these hybrid water heaters are something like spray foam and they have a 20 year re-payment vs. a standard unit... thats great, especially on something that has an average life of 8-10 years.

ETA: guessing you would gain more energy savings by adjusting your hot water heater temps depending on season. I turn mine down in the late spring into summer and then turn them up slightly going into winter.

 

[Sean the Nailer]

To go along with this discussion, does anyone here have any kind of 'heat exchanger' on their 'tub drain' with the cold-water supply plumbed into it? (did that get worded correctly?)

For those of us who like hot showers, the 'hot water' going down the drain is put to best use by pre-heating the water going INTO the hot-water tank. Reclaim all them BTU's that your literally 'flushing' down the drain.

Anyone?

 

[plong]

I won’t ever give Rheem another $.001 (yes, that’s one tenth of one cent...) of my, or anyone else’s, money. That company‘s character was fully exposed to me years ago when they did everything they could to dodge responsibility for what was proven to be a design defect in their gen 1 80% furnace igniter... I said then, and I’ve held true ever since, no Rheem, never.. ever...

trust me, there are better options, no matter what it is you may be considering purchasing.

 

[addertooth]

I was in a hurry, so I will clarify on the hard water statement. A regular electric tank heater has sacrificial magnesium anodes to prevent lime buildup inside the tank. Depending upon the hardness of your water, they may have to replaced every few years.

For water heaters that use "heat exchangers" there is a more complex purging and de-liming requirements to keep them operating nominally. A classical tank is easier to deal with high lime water (by more frequently replacing your anode rods), but for a heat exchanger style heater (and hot water on demand heaters), it is a bit more complex. Many home owners wonder why they die so frequently in high-lime water locations.

 

[Ravenworks]

I was in a hurry, so I will clarify on the hard water statement. A regular electric tank heater has sacrificial magnesium anodes to prevent lime buildup inside the tank. Depending upon the hardness of your water, they may have to replaced every few years.

For water heaters that use "heat exchangers" there is a more complex purging and de-liming requirements to keep them operating nominally. A classical tank is easier to deal with high lime water (by more frequently replacing your anode rods), but for a heat exchanger style heater (and hot water on demand heaters), it is a bit more complex. Many home owners wonder why they die so frequently in high-lime water locations.

That holds true for any tank, it's considered maintenance.
See my post above

 

[plong]

I was in a hurry, so I will clarify on the hard water statement. A regular electric tank heater has sacrificial magnesium anodes to prevent lime buildup inside the tank. Depending upon the hardness of your water, they may have to replaced every few years.

For water heaters that use "heat exchangers" there is a more complex purging and de-liming requirements to keep them operating nominally. A classical tank is easier to deal with high lime water (by more frequently replacing your anode rods), but for a heat exchanger style heater (and hot water on demand heaters), it is a bit more complex. Many home owners wonder why they die so frequently in high-lime water locations.

Same is true (sacrificial anode...) for a storage tank style gas unit. It’s the “tankless“ units, whether they be some flavor of electric, or gas, where things get (much) more complicated. And that says nothing about the complications related to input temperature versus flow rate... constant hot water? Yup, no problem... Constant volume...? Um... that would be a hard no...!

 

[RPN]

I have a heat pump on my (separate) hot water cylinder, with a wetback from the fire for winter heating. My house is off grid and the electricity is all solar.

The tank is 300l, which acts as a reasonable heat bank, and the multiplier from the heat pump works a whole lot better (between 1.8 - 3.8x multiplier) than an element would. The cost was less important to me when building as efficiency, but the calcs are easy enough to do if you know your kw price.

 

[Bullfrog08]

I never like to be a guinea pig for this new shit. More components....more problems!

 

[BuildingConceptsllc]

We use em when they can be placed in the right location. They can absolutely save that much money per year. It's all about where they are located so that you can actually use the full effect of the unit. Like anything else, it's choosing the right system for your requirements /needs/ placement....

 

[hlee]

Well, it’s not an option, but I’m throwing my 2 cents in anyway. Last month, when that winter storm knocked out power (electricity) here in houston, it sure was nice to be able to take a hot shower thanks to the natural gas water heater.

 

[greentick]

We put one in a couple of months ago (Rheem 80gal hybrid). Demos: Deep South. We have 8 kids and homeschool (so everyone's home pretty much all the time, lots of water usage). We use a water softener. The WH is in an unclimate-controlled garage.

Normally, come July/August/Sept the garage is untenable for reloading (that's where my setup is). This includes when I work a midshift and get home in the middle of the night. So there is plenty of hot air in the garage most of the year for the heat pump to do it's thing. So far the garage is noticibly cooler than previously but we have not hit the bad months yet. There is a significant volume of cold air coming out of the unit. You will need to have somewhere for the condensate to go - drain line to somewhere.

The majority of the time I leave it in "Energy Saver" mode. There is "heat pump," "vacation," "high output," etc. We have seen a definate decrease in our electric bill but I think we need more time to fully assess that to make a definate call. You can adjust on the easily accessible control panel or hook it into you wi-fi and control it from you phone (I don't do "smart" homes, so haven't tried that).

I didn't know Rheem was on a shitlist, so it is what it is.

We decided to guinea pig it though I was like WTF is a "hybrid." Seems like a good fit for the South, some people evidently run that cold air into their living space. I am really curious if, in the middle of the night, I will be able to get in reloading. It helps me wind down at 0-dark thirty.

 

[kennyg]

You might check with your local electric company. Some have rebates for the heat pump hot water heaters.

 

[Bullfrog08]

Deep thoughts.......

Is it a hot water heater, warm water heater or cold water heater? Maybe just a water heater? It does keep the hot water hot, so maybe it is a hot water heater? Maybe depends on the definition of hot as it relates to your personal definition of hot. Maybe when you turn it up, it becomes a hot water heater for that brief period? But, the previous temp might not have been the users definition of hot.

We dont call a freezer, a freezing freezer, right?

Seems like adding "hot" may be a little reduntant to a water heater.

Sorry........carry on!

Oh, if you stick a cold/warm/hot water heater in a hot location, like an attic, does that make it a hybrid? Whats the definition if you over insulate it?

 

[riverside jeep]

I will be installing a 65 gallon model in my brothers new house in a few days. He opted to put the water heater in a closet in the house and I am ducting the exhaust into the attic. The theory we have is that he heats his house with wood stove so the heat exchanger will use that heat for the water and then pump the cool air into the attic were it will be vented to outside. This being the great state of Komifornia he is required to produce 100% of his energy usage from a renewable source so in the energy calculations it was required the he use a heatpump water heater and also a heatpump heater/ ac. It is a new technology for both of us. I'll be installing a 7700 watt grid tie solar array and if everything works as planned he should have a zero energy bill at the end of the year. My only concern with the water heater is of the noise, we have never heard one run.

 

[Sean the Nailer]

Deep thoughts.......

Is it a hot water heater, warm water heater or cold water heater? Maybe just a water heater? It does keep the hot water hot, so maybe it is a hot water heater? Maybe depends on the definition of hot as it relates to your personal definition of hot. Maybe when you turn it up, it becomes a hot water heater for that brief period? But, the previous temp might not have been the users definition of hot.

We dont call a freezer, a freezing freezer, right?

Seems like adding "hot" may be a little reduntant to a water heater.

Sorry........carry on!

Oh, if you stick a cold/warm/hot water heater in a hot location, like an attic, does that make it a hybrid? Whats the definition if you over insulate it?

Tuna Fish

synonymous with "Corned-Beef Cow"

Pork Chop Pig

Chicken Breast Buzzard

 

[jg6.5]

I never like to be a guinea pig for this new shit. More components....more problems!

I'm on board with this logic.

I'm a PM for a commercial mechanical contractor, and I've yet to ever see one of the hybrid type heaters spec'd on a project. By and large everything we install are gas-fired units from AOSmith or State, or Lochinvar if someone is feeling fancy. At most they're condensing-type where you have to have condensate neutralization kits for the condensate that is produced. We don't see a whole lot of electric heaters due to the size of the heater itself, the electrical demand would be pretty high - couple that with natural gas being pretty cheap in Oklahoma, and you end up with the above being our "norm".

OP, I realize purely gas-fired isn't an option as you stated...just adding my 2 cents. Given your situation I wouldn't necessarily be opposed to a hybrid unit, but as others have stated, I'd be reaching out to plumbing supply houses as opposed to a big box store. Call a few up and talk to their outside sales rep if they have one. They typically have a better relationship with the manufacturer and can more readily address concerns or any warranty issues if they arise.

 

[fdkay]

Tuna Fish

synonymous with "Corned-Beef Cow"

Pork Chop Pig

Chicken Breast Buzzard

ATM Machine

 

[DarnYankeeUSMC]

Walkie talkie = woman

 

[greentick]

...My only concern with the water heater is of the noise, we have never heard one run.

Similar to a very quiet window unit AC. There is a fairly quiet fan. If it's in a closet it shouldn't be too bad.

 

[Schroedernd]

I've had a geospring hybrid 1st gen unit for about 6 years now. Got a ton of state and fed rebates at the time and paid like $400 for it. Had one issue a few years in that was covered by warranty. Works well and added feature is it keeps the garage cooler and takes the moisture out of the air (have to remember to dump the bucket). That said when it goes out I'm getting on demand gas as itll save me even more money...

 

[Dead Eye Dick]

I sure hate that tankless is not an option. Our home was built with the hot water heater in the attic. Had a splash tank around it and a drain but when it gave up, it gave up. fortunately, it only leaked over the laundry room. We replaced with tankless and never been more pleased.

But as you said, not an option. So, what ever you choose to go with, make sure it is effectively drained to a safe area. Even a flood in your garage could be an issue.

 

[GrumpyOleFart]

Are you on mains?
If your water is hard, place a filter between your POE and water meter/main line to the house.
A twin filter, pre or coarse filter, then a carbon filter.
Check them every once in a while, to get an estimate of what crap is in your line.
This will greatly extend the life of your system.
I fitted one to our house when we built it.
Our heater is a Rheem, made here in Perth.
If it freezes around your area, make sure you have the expansion breather snorkel on your panels. If it doesn't frost or freeze in your area, you don't need one.

 

[Major Wader]

Curious as to why tankless is not an option. There are both gas and electric tankless available, though we installed gas.

I will never build or own another house without a tankless water heater. Never run out, only heats when the water is running.

Same curiosity regarding tanked gas.

 

[jg6.5]

Curious as to why tankless is not an option. There are both gas and electric tankless available, though we installed gas.

I will never build or own another house without a tankless water heater. Never run out, only heats when the water is running.

Same curiosity regarding tanked gas.

Whole house (i.e. high flow rate) tankless electric models require quite a bit of power - an 8 gpm 36 kW Rheem model is 240V/150A and recommends 8 AWG wiring to the unit and 4-40A breakers in the panel. That's asking a lot of a typical 200A residential panel, especially if most/all of the other appliances in the house are electric as well.

I know others have mentioned Rheem being unfavorable, it was just the easiest spec sheet I could find. Electrical requirements for similar electric heaters from other manufacturers should be similar.

 

[Major Wader]

OK, so why is gas not an option? Again, just wondering. I installed a propane tank specifically to have gas tankless, as NG not available.

My propane only runs cooktop, tankless, and backup genset.

 

[Dead Eye Dick]

OK, so why is gas not an option? Again, just wondering. I installed a propane tank specifically to have gas tankless, as NG not available.

My propane only runs cooktop, tankless, and backup genset.

We run our tankless water heater with propane and our stove. Not had any issues yet with the use of the propane in the water heater. Now, our plumber, for safety reasons as well as trying to work out the venting issue, put ours outside at the point where the propane comes into our home. Venting was the issue, and installing venting in a competed home, was going to be fairly complicated and expensive. All of this would seem to a moot point when building new.

 

[tomcatmv]

To the OP. As a retired Mechanical contractor and engineer with over 40+ years in commercial and large multi-family construction, I would not be concerned about the heat pump technology. It is proven and reliable. I'm not familiar with Rheem's offering but have installed a lot of LG hybrid heaters in conjunction with variable refrigerant flow (VRF) systems in several mid to high rise condo/apartment projects with no reported problems. Look for one that has an inverter driven scroll compressor for max efficiency.
Even though our home here in Central TX is only 6 years old, I'm thinking about putting one in because we're all electric and could help cool our garage.

 

[jg6.5]

OK, so why is gas not an option? Again, just wondering. I installed a propane tank specifically to have gas tankless, as NG not available.

My propane only runs cooktop, tankless, and backup genset.

Just speculation here, but a propane tank may not be feasible, available, or allowed (not sure if he's inside city limits or other AHJ that may have rules against it) - again, just speculation based on the OP's comment of gas not being an option (may have already researched this).

To the OP. As a retired Mechanical contractor and engineer with over 40+ years in commercial and large multi-family construction, I would not be concerned about the heat pump technology. It is proven and reliable. I'm not familiar with Rheem's offering but have installed a lot of LG hybrid heaters in conjunction with variable refrigerant flow (VRF) systems in several mid to high rise condo/apartment projects with no reported problems. Look for one that has an inverter driven scroll compressor for max efficiency.
Even though our home here in Central TX is only 6 years old, I'm thinking about putting one in because we're all electric and could help cool our garage.

OP - good info here from someone with direct experience.