Author Topic: heat pump water heater  (Read 8022 times)

dilinger

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heat pump water heater
« on: August 06, 2014, 06:19:18 PM »
My house has a 10+ year old electric hot water heater.  I've only lived here for a few months, so I don't have records on electricity usage yet.  However, the energystar label on the unit claims 5106 KWH/yr.

My local utility (Seattle City Light) is advertising a GE hybrid heat pump/electric water heater (MSRP $1200) for $300.  It claims usage of 1830 KWH/yr.

At $0.12/yr, that's $612 operating cost for my old water heater, $219 for the hybrid heat pump water heater.  That's.. insane, especially for for unit cost of $300.  What's the catch?  Why aren't more people on here talking about this?

I'm aware that it's noisy, but it'll be located next to an oil furnace in the (conditioned) basement (the oil furnance needs to go, too, but all of the local rebates are for replacing electric heat only, not oil).  If I do get it, is there any reason not to do the install myself?  Watching youtube videos (ie, http://www.youtube.com/watch?v=OJz4-7jzRt4 , http://www.youtube.com/watch?v=IM_MxzIQfwE ) , it looks pretty darned easy other than carrying the thing around.

MMM

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Re: heat pump water heater
« Reply #1 on: August 06, 2014, 08:51:19 PM »
Hey Dilinger!

Just wanted to throw in my own reassurance that this is a great idea. The heavily subsidized price makes it a no-brainer, and I feel that everyone with electric heat should be considering the upgrade, even without the subsidy*.

They are more complex than a traditional water heater, so there is a certain chance of breaking or needing maintenance over its lifespan. You might factor that in by reducing calculated savings a bit. But again, at $300 you would ignore this factor.

As for installation: it is indeed quite straightforward: cold water in, electricity in, hot water out. I've changed many water heaters and never run into trouble other than a bit of water to towel up.


*GP Conservation at http://www.gpconservation.com/ has these things and I think they still honor the "MMM" discount code for free shipping and 5% off. I don't get a commission or anything, I just like the store and the guy who manages it.



dilinger

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Re: heat pump water heater
« Reply #2 on: August 07, 2014, 12:31:19 AM »
Thanks MMM!

The one I looked at had a 10yr warranty (on parts), which seems perfectly reasonable to me.

I'll need to figure out some drainage, as my current heater has its pressure relief value drain into an unfinished area of the basement.  It's actually one of the weird things about my basement; it's mostly finished, but the subfloor that's visible is gravel with a thin layer of concrete or something smushed down on top of it.  Underneath the walls where concrete wasn't put down, that's where the drain dumps out.  I have no idea what's under there, but in various places that have had water infiltration, the concrete is pretty cracked.  I've been meaning to try digging down to see what's under there, as adding slab insulation, underfloor heating, and possibly a perimeter drain is on my long-term todo list.

I love the idea of a condensate drain providing some dehumidification down there, too.  Seems like a nice additional feature for a basement space in the wet Pacific NW..

big_owl

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Re: heat pump water heater
« Reply #3 on: August 07, 2014, 10:16:51 AM »
Another thing to consider in your operating costs is that all a heat pump really does is move heat from one place to another.  You're basically pulling heat out of the room that the heater is located in and then transferring it into the hot water tank.  This could be good if you live in a warm climate and would be using AC anyway.  As you already mentioned, it will also have the added benefit of helping to dehumidify whatever room the water heater is located in.

However in a cold climate you'll have to replace the heat that you are removing from the room or else it will get cold and the water heater will need to run much more to heat the water, or the backup electric heater element will come on negating any savings you thought were getting.  If you already heat the room with natural gas or a heat pump then you'll come out ahead.  Oil heat will result in less savings if prices are anything like out East.  However if you end up heating with electric resistance heat in the winter then the savings will be much less.

Also, consider the size of the room the heater is located in.  If it's a small utility room, then you'll need to have some way of circulating more air into it so that the heat pump will have access to warmer air as it cools the room down.  Since it appears you're in Seattle then I'm guessing it doesn't get too cold in the winter, so you'll probably be ok.

dilinger

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Re: heat pump water heater
« Reply #4 on: January 22, 2015, 06:03:17 PM »
Hey Dilinger!

Just wanted to throw in my own reassurance that this is a great idea. The heavily subsidized price makes it a no-brainer, and I feel that everyone with electric heat should be considering the upgrade, even without the subsidy*.

*GP Conservation at http://www.gpconservation.com/ has these things and I think they still honor the "MMM" discount code for free shipping and 5% off. I don't get a commission or anything, I just like the store and the guy who manages it.

Thanks for the link and discount code!  It was actually for 10% off.  I just ordered one, since I had missed Home Depot sale back in August.

For others who are interested, GP Conservation not only has a good price on the GE Geospring Hybrid hot water heater ($945 instead of $1200MSRP), but right now they also have several scratched (but new and warrantied) models that they're selling for $755.  Great mustachian price if you're willing to do the install yourself and handle the slightly higher risk of warranties/repairs!

https://www.gpconservation.com/water-heaters/heat-pump-water-heaters.html

superathlete

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Re: heat pump water heater
« Reply #5 on: January 24, 2015, 06:06:57 AM »
I echo that this is a good idea.  I had one when I lived in the south.  When not running the home heater, be sure to use the economy mode to keep the resistance strips off.  Much more efficient than the hybrid mode.

JLee

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Re: heat pump water heater
« Reply #6 on: April 23, 2015, 10:15:44 AM »
I just checked GP Conservation and they are blowing out AirGenerate water heaters for REALLY cheap:

https://www.gpconservation.com/water-heaters/heat-pump-water-heaters.html

No manufacturer's warranty (1yr from vendor), but at that price I will grab one.  $629.90 delivered for an 80 gallon unit. I am tempted to buy two, but if it breaks after a year I'll figure something else out.
« Last Edit: April 23, 2015, 10:52:10 AM by JLee »

dilinger

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Re: heat pump water heater
« Reply #7 on: April 25, 2015, 03:01:28 PM »
Wow!  I'm seeing $500, that's crazy cheap.

Also note that Lowes now has a sale on the NEW model of GE Geospring heat pump water heaters for $700: http://www.lowes.com/pd_665053-83-GEH50DFEJSR_0__?productId=50335967

I'm aware of 3 models of Geospring HPWH: the grey top ones that had a whole host of issues/failures, the 2nd version that I bought (and is running like a champ), and the model that came out in 2015.  The newest model is what's on sale.  More efficient, but also has a leak flaw during manufacturing that hopefully GE gets a handle on.

Merrie

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Re: heat pump water heater
« Reply #8 on: April 25, 2015, 06:00:49 PM »
Anyone with experience with the AirGenerate ones? We were looking at a GE one, but it's hard to turn down something that's 50% cheaper, unless it's a piece of garbage.

Sid Hoffman

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Re: heat pump water heater
« Reply #9 on: April 27, 2015, 08:06:01 AM »
the energystar label on the unit claims 5106 KWH/yr. ... heat pump/electric water heater ... 1830 KWH/yr. ... What's the catch?  Why aren't more people on here talking about this?

The two main factors in water heating cost are the incoming water temperature and how many people live in the house.  For example, now that I live largely alone again and have access to my hourly electric usage, I can easily spot with good precision how much energy is used when I take a hot shower; something around 1.5 kw/h average over the year.  Also, by comparing my base electric usage with my electric hot water heater shut off versus maintaining temperature, it appears to be around 0.05kw/h/h to maintain.  So in other words, I estimate my water heating around 2.7 kw/h for showers.  Clothes washing probably brings it up to around 3kw/h/day.

That's about 1100 kw/h/year, which is obviously way below the 5100 you see listed on a conventional water heater.  Factors for me are a high average inlet temperature for the incoming tap water as well as there only being, say, 1.25 people living here (I only have partial custody of my son).  So first things first, I would make sure to adjust the estimated energy usage based on how many people live in your area, then perhaps some kind of further adjustment based on the average cold water temperature for your area.

JLee

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Re: heat pump water heater
« Reply #10 on: April 27, 2015, 08:53:15 AM »
Anyone with experience with the AirGenerate ones? We were looking at a GE one, but it's hard to turn down something that's 50% cheaper, unless it's a piece of garbage.

I called GP Conservation and they said the 66 gallon AirGenerate model used to be about $2000, but AirGenerate went out of business due to a massive recall in 2013. The woman I spoke with said she hasn't seen any of the newer model water heaters come back - apparently they've fixed the flaw, but they were hit hard enough that it took the company down.  They are selling the remaining stock at less than wholesale and GP Conservation is providing a one year warranty.  I figure it'll likely come close to paying for itself by the time the warranty period runs out, and I didn't want to drop $2000 on another one.

I was looking at GE models but I checked Amazon reviews and they were terrible, so I took a risk and went for AirGenerate at a really low cost.

dilinger

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Re: heat pump water heater
« Reply #11 on: January 30, 2016, 11:05:02 PM »
So not only did I get a $500 rebate from the city, but I also just discovered that the feds have a $300 tax credit:

http://energystar.zendesk.com/hc/en-us/articles/211437758-Is-there-a-tax-credit-for-electric-heat-pump-water-heaters-

So total HPWH cost to me?  $0.  Win!

Merrie

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Re: heat pump water heater
« Reply #12 on: February 01, 2016, 05:55:35 PM »
Good to know! We got the water heater I mentioned in my comment and I'll see about claiming it. We also replaced our HVAC system. I might have just maxed out the lifetime energy efficiency tax credit. Why is it so darn low?

We have had the water heater for about 6 months and done fairly well with it. We have not had any problems, we have just had to figure out the programming. It can be set to only heat at certain times, but that wasn't working really well for us because we'd have scenarios like, one person takes a shower or we run the washing machine on hot, the tank is flooded with cold water, bringing its temperature down to "meh" degrees, and the next person gets a lukewarm shower. I think that setting might be helpful for people who have different on-peak and off-peak energy prices, but I don't think we do.

dilinger

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Re: heat pump water heater
« Reply #13 on: February 01, 2016, 06:56:43 PM »
Yeah, I operate mine in heat-pump-only mode.  It works perfectly about 90% of the time, but every once in a while my wife will get a cold shower because she gave the kid a bath a few hours earlier, and then a housemate also did dishes or took a shower or something just before she did.

The GE has a "turbo" mode that would be useful if we knew in advance that there wasn't any hot water - the problem is that you don't know until you start showering.  You're okay for the first few minutes, and then suddenly the water's cold.

I wish the display in front just showed the current water temperature.  It feels silly using a more aggressive heating mode when the majority of the time when someone uses up the hot water, there's no one else needing any for another 12 hours.

BudgetSlasher

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Re: heat pump water heater
« Reply #14 on: February 02, 2016, 05:27:31 PM »
I am really considering one of these. Anyone have experience in a colder climate with one?

We currently have a indirect water heater (Phase III) off of an oil boiler.

But there are a couple issues with it, first the aquastat (temperature control) is a guessing game ~45 dollar part. Second, it is 27 years old. Third, in all that time I doubt it has ever been flushed (we're on well water so you can bet there is some sediment) and apparently the kit is ~$64 to drain this thing; I need to see if I can get a work around. Fourth, it should be plumbed to the boiler with 1 inch pipe, but is plumbed with 3/4 in pipe. Somewhere in all of that lies a problem, it is not putting out near its rated first hour or sustained hot water ratings; this is not normally a problem except when trying to use the giant (and I do mean giant) bathtub. Plus the boiler runs during the summer to provide hot water. Basically the cost and remaining life are unknown.

On the flip side the link posted for a 50 gallon GE heat pump, minus the 10% MMM code, minus the $300 federal tax credit, minus the state $500 rebate, means a 90 dollar water heater. There would be the associate costs of fittings and wiring to get it in (some I already have) and a mixing valve (allows hotter tank temperature to keep anything that might grow in well water down, plus extend the amount of temperature-safe "hot" water. The downside is my location and house mean that the unit would be placed in a unheated basement year-round (roughly 50 F in the winter and maybe 72 F on at the worst of summer) so not really getting as much free heat as other locations. Numbingly cold groundwater, especially in the winter. On the plus side it would either replace or reduce the necessity to run a dehumidifier during the summer months.

Merrie

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Re: heat pump water heater
« Reply #15 on: February 02, 2016, 06:25:16 PM »
I figured that in our case, even if the heat pump can't keep up in heat pump mode 100% of the time and starts using more electricity, it's still more energy-efficient than its ancient predecessor which, while still functional, was nearing the end of its lifespan, so I saw zero downside to replacing it with the heat pump water heater rather than a typical one and not much downside to replacing it when we did rather than waiting until it actually died. We could have maybe squeezed a few more years out of it, but meh.

It's winter now in Ohio. We haven't had problems so far.

talltexan

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Re: heat pump water heater
« Reply #16 on: February 03, 2016, 07:18:56 AM »
I'd like to install a heat pump water heater, but it looks like my current (tanked) one is gas-powered. Is a conversion to electric easy? I don't see any evidence that a gas-powered heat pump water heater is a real thing.

JLee

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Re: heat pump water heater
« Reply #17 on: February 03, 2016, 12:29:43 PM »
I'd like to install a heat pump water heater, but it looks like my current (tanked) one is gas-powered. Is a conversion to electric easy? I don't see any evidence that a gas-powered heat pump water heater is a real thing.

Gas water heaters are far more efficient than electric - I would stay with what you have.

paddedhat

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Re: heat pump water heater
« Reply #18 on: October 20, 2017, 03:37:44 PM »
We live in a fairly temperate climate, in South Central PA. We bought an older home from a couple that installed a GE unit in 2011. The good part? It makes a massive difference in our electric bill. The downside? The unit is a piece of shit, as in Yugo quality shit. The original owner had a significant repairs done under the full warranty. Earlier this year it failed again and I called the 800 # and spoke to IIRC, Bradford White, the company who bought the whole mess out. They listened to my issue and, as far as I can tell, shipped me EVERYTHING but the tank and sheet metal, for N/C. It the took an entire afternoon and $375 for the factory authorized tech. To rebuild the unit. He told me that his large regional appliance dealer was still a big fan of heat pump HWH, but no longer willing to deal with GE products.
At this point, if mine can actually perform without issue for a few years, I will be happy. When it finally quits I will replace it with another heat pump. I doubt it would be a GE brand, however.

Papa bear

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Re: heat pump water heater
« Reply #19 on: October 20, 2017, 05:33:38 PM »
I switched to heat pump hot water tank about 7 months ago. I saw a significant decrease in my electric bill, more than I calculated based on the estimated usage that the manufacturer had for the old and new unit.

My house was all electric, but I added a gas line when they extended to my neighborhood. I stuck with electric due to not having great options to vent out units.

And has anyone noticed that there have been some threads resurrected from the dead on these DIY parts of forums?  All of them are first time posters with links to some product...


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Re: heat pump water heater
« Reply #20 on: October 21, 2017, 07:58:43 PM »
And has anyone noticed that there have been some threads resurrected from the dead on these DIY parts of forums?  All of them are first time posters with links to some product...

Yeah.  Use the "Report to Moderator" link at the bottom of posts.  They're spammers.
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iamsoners

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Re: heat pump water heater
« Reply #21 on: November 13, 2017, 09:44:15 PM »
I've been day-dreaming about a complete redo of the HVAC system in our 100 year old house. We would put mini-splits in for conditioning and use electric for cooking.  That would leave only our hot-water heater on natural gas.  I don't have great numbers on our hot water use (is there a way to meter this well? we currently use some gas for cooking so I can't take from the bills directly) but from studying our bills it looks like there's about $15-20 spent on gas hook-up fees and taxes and such. My thought is, does it make sense to switch to a heat pump water heater even though it's less efficient than gas? Especially because it seems like we, as a society, are heading towards electrification (I live in an area with the dirtiest grid in the country--lots of coal--but the usage ratio changes for the better every year) and I would personally consider installing pv solar some time in the future.

Syonyk

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Re: heat pump water heater
« Reply #22 on: November 13, 2017, 10:25:14 PM »
First check to see if you can actually disconnect gas. Lots of places won't let you.
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iamsoners

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Re: heat pump water heater
« Reply #23 on: November 14, 2017, 05:33:45 PM »
Hmm, good to know...

big_owl

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Re: heat pump water heater
« Reply #24 on: November 14, 2017, 06:11:07 PM »
My electric resistance water heater shit the bed this weekend (was getting stuck in the 'on' position - kinda scary) so I pulled the trigger and now have a brand new A.O. Smith 50gal HP hybrid water heater in my basement.  I need to do the plumbing this weekend to physically get it lined up, but will report back after I start using it. 

paddedhat

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Re: heat pump water heater
« Reply #25 on: November 14, 2017, 07:54:34 PM »
My electric resistance water heater shit the bed this weekend (was getting stuck in the 'on' position - kinda scary) so I pulled the trigger and now have a brand new A.O. Smith 50gal HP hybrid water heater in my basement.  I need to do the plumbing this weekend to physically get it lined up, but will report back after I start using it.

I hope you love it. The dealer that rebuilt my GE hybrid has switched to selling the A O Smith heaters. The tech. told me that they have been a trouble free heater, as were the very last generation of GE products, before they gave the business up.  We moved from an all electric house with newer appliances, to our current one, with newer appliances AND the heat pump HWH, both served by the same electric co. My electric bills seem to be running about $35 a month less with the heat pump. Good luck with yours. 

big_owl

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Re: heat pump water heater
« Reply #26 on: November 25, 2017, 09:28:23 AM »
Well it's been a little over a week of using my heat pump water heater and it's been pretty much a non-event.  So far my hot water experience has been identical to the resistance heat unit I replaced.

I installed the heater where my old one was - in my finished basement in a room about 2.5 times the size of your average walk-in closet (fully insulated and with a floating subfloor).  Before the unit was installed I was averaging about 69F in the room, now it's about 65F.  And that's only when it's been running for a while (after we both take showers, for example).  Most of the time when we're not using hot water the room sits around 67-69F so no real difference.  If the heater was in a small closet then there would definitely be problems with temperature control I think. 

It can be run in "electric" (resistance) mode, "hybrid" mode (HP primary with resistance backup), "efficiency" mode (HP-only), and "vacation" (not sure what this does yet - I assume it's like an off switch?).  Once I realized I didn't even need the backup heat I just set it to "efficiency" mode and left it there.  Should drop my e-bill quite a bit. 

My old heater was 80gal but since it's just the two of us with no plans for kids I bought the 55gal HP model.  So far we can both take showers in HP-only mode without any loss of hot water.  I bet for a family of four the 80gal would be required for that luxury though. 

It's much more quiet than I was expecting, about the same noise as a loud fridge when it's running.  I don't hear it with the door to my storage room closed.  About the only downfall I can see if potential repair costs if something goes bad.  HPs are a pretty mature technology and A.O. has been around for a while so I'm hoping for the best there. 

Oh yeah, and my unit was about $1300 all-in from Lowes.  My electric company is giving us a $500 cash rebate for it, and the estimated yearly savings is around $400/yr over my old unit.  So just about two years for full payback.  I could have sold the old unit but didn't want to hassle with CL so I just gave it away to some guy.

Syonyk

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Re: heat pump water heater
« Reply #27 on: November 25, 2017, 10:24:37 AM »
Oh yeah, and my unit was about $1300 all-in from Lowes.  My electric company is giving us a $500 cash rebate for it, and the estimated yearly savings is around $400/yr over my old unit.  So just about two years for full payback.  I could have sold the old unit but didn't want to hassle with CL so I just gave it away to some guy.

Wow!  That's... insanely good economics on that.  I'll definitely have to look into those at some point - I don't think it makes sense to replace my resistive heater quite yet (since it's about a year and a half old), but that's awesome - and helps with the cooling during the summer, at least if you're in a cooling dominated climate.
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paddedhat

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Re: heat pump water heater
« Reply #28 on: November 25, 2017, 11:41:20 AM »
It also helps with dehumidifying the basement in the warm months. In the summer, mine extracts about 12-15 gallons of water, out of the air, every month. The report of the AO Smith unit being fairly quiet is interesting. MY GE is unacceptably loud, and would be a big issue if it was located adjacent to a bedroom or office space.

big_owl

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Re: heat pump water heater
« Reply #29 on: November 25, 2017, 12:22:15 PM »
Yeah I didn't even know I was going to get a rebate from the local utility until I placed the order on Lowe's.com and it notified me it was eligible.   Pleasant surprise.   Even now it is condensing water out of the basement and it's heating season...so I know it will be very useful in the summer. 

As for noise, I have read the geospring units are rather loud.  The compressor itself is no louder than my minifridge compressor.  The fan is where most of the noise comes from but they've obviously put some engineering effort into fan motor and blade noise. I wouldn't have any issues if my bedroom was the next room over. 

BudgetSlasher

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Re: heat pump water heater
« Reply #30 on: November 25, 2017, 12:52:42 PM »
It also helps with dehumidifying the basement in the warm months. In the summer, mine extracts about 12-15 gallons of water, out of the air, every month. The report of the AO Smith unit being fairly quiet is interesting. MY GE is unacceptably loud, and would be a big issue if it was located adjacent to a bedroom or office space.

The load taken off the dehumidifier is big; since switching from indirect to heat pump in may I have only noticed a couple hundred extra KWh added (of course there have been other changes as well over that time).

I have a Rheem and they are not as silent as an electric, I would say the mini-fridge is a good comparison. It is in the basement and is slightly louder than the deep freezer, but it is much quieter than the dehumidifier, washer, and dryer all of which are also located in the basement.

dilinger

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Re: heat pump water heater
« Reply #31 on: November 26, 2017, 11:29:10 PM »
Yeah, my GE Geospring is pretty noisy.  It's in a storage room in the basement, so it's not an issue.

I've had it now for a bit over two years.  Not a single problem with it.  I originally ran it in efficiency mode, but my wife complained during the winter when we had people staying with us and she was stuck taking the last shower.  Now it's in hybrid mode, and I haven't noticed any hot water problems.  At some point I'll probably switch it back to efficiency mode (especially since we don't have plans for visitors for a long time), and see if she notices. :)

Electric bills were initially lower, but we've also switched from oil heat to some mini splits, so our electric usage has actually gone up (but overall heating costs have gone down).

Sid Hoffman

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Re: heat pump water heater
« Reply #32 on: December 01, 2017, 10:27:25 AM »
Yeah, my GE Geospring is pretty noisy.  It's in a storage room in the basement, so it's not an issue.

I've had it now for a bit over two years.  Not a single problem with it.  I originally ran it in efficiency mode, but my wife complained during the winter when we had people staying with us and she was stuck taking the last shower.  Now it's in hybrid mode, and I haven't noticed any hot water problems.  At some point I'll probably switch it back to efficiency mode (especially since we don't have plans for visitors for a long time), and see if she notices. :)

Electric bills were initially lower, but we've also switched from oil heat to some mini splits, so our electric usage has actually gone up (but overall heating costs have gone down).

I just wanted to take a moment to say thank you for this and many of the other reviews from heat pump water heater users.  I just moved to a new 2-bed home this year that is the first one I've ever been in with natural gas.  As such, it uses gas for home heat and water heating, although everything else (stove, dryer, no fireplace) is electric.  During the summer months it feels pretty wasteful to have a $15.50 natural gas charge with only $3 being actual gas usage for water heating.  I like the idea of going fully electric at some point and turning off natural gas entirely (and avoiding about $140/yr in meter charges and fees alone) but I also work from home and my office area is just one wall away from the water heater.  This thread gives me encouragement though, thank you to all who've contributed!

m8547

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Re: heat pump water heater
« Reply #33 on: December 22, 2017, 11:07:22 AM »
I'm planning on replacing my resistance electric water heater, and I can't decide between gas or heat pump. There used to be a gas water heater there, so there's a perfectly good gas line and flue where the water heater goes. But is it worth going with a heat pump unit? The rebate from my utility company makes it about the same price.

Heat pump pros:
  • According to the energy guide label, it's half the cost of gas to operate.
  • I could pipe the outlet into the house for free cooling in the summer, or into the crawlspace for free dehumidification, or outside during mild weather. I'm picturing a damper that lets me select several locations base on the season
  • In the future it could be more environmentally friendly, when our electricity comes from more renewable sources (right now the majority is coal)
  • I could switch to a peak demand plan and lower my electric rate to $0.04/ kwh if I carefully manage my usage (it's $0.10 right now on the standard plan), saving even more than what's assumed on the energy guide label

Heat pump cons:
  • I expect our electricity cost to significantly increase in the future.
    I wouldn't be surprised if it doubles.
  • My house only has 125A service, so I need to be careful not to add too many things. If I add up big loads such as the stove, dryer, water heater, and AC that's almost 90A. I'd like to get another mini split and an electric car at some point in the future. So gas hot water might be nice to free up electric capacity.

Gas pros:
  • It's simple proven technology
  • It might work in a power outage, depending on the unit I get.

Gas cons:
  • I'd like to get away from using fossil fuels eventually
  • I think standby loss is a little higher than electric since the chimney in the center of the water heater is uninsulated.
  • I also expect the price of gas to go up in the future, but likely not as much or as quickly as electricity

robartsd

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Re: heat pump water heater
« Reply #34 on: December 22, 2017, 12:19:47 PM »
I just wanted to take a moment to say thank you for this and many of the other reviews from heat pump water heater users.  I just moved to a new 2-bed home this year that is the first one I've ever been in with natural gas.  As such, it uses gas for home heat and water heating, although everything else (stove, dryer, no fireplace) is electric.  During the summer months it feels pretty wasteful to have a $15.50 natural gas charge with only $3 being actual gas usage for water heating.  I like the idea of going fully electric at some point and turning off natural gas entirely (and avoiding about $140/yr in meter charges and fees alone) but I also work from home and my office area is just one wall away from the water heater.  This thread gives me encouragement though, thank you to all who've contributed!
If you're using conventional electric stove and dryer, you'd probably save more by switching these to natural gas instead. If the cooktop is induction and the dryer is a heat-pump dryer, then going high-efficiency electric all around to eliminate gas connection costs might make sense if you have really good electrical rates.

Heat pump pros:
  • According to the energy guide label, it's half the cost of gas to operate.

Heat pump cons:
  • I expect our electricity cost to significantly increase in the future.
    I wouldn't be surprised if it doubles.

Gas cons:
  • I also expect the price of gas to go up in the future, but likely not as much or as quickly as electricity
I'd do a further study of the costs if this is all true. If you expect the HP water heater to cost half as much as the gas water heater initially, electrical prices eventually doubling would still have the HP water heater winning.

m8547

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Re: heat pump water heater
« Reply #35 on: December 22, 2017, 05:22:00 PM »
My heat is gas, so it would be impractical to eliminate gas service. My mini splits only work as air conditioners, but even if they were heat pumps they only cover a couple rooms. We don't need much air conditioning here. The only room that really needs it doesn't have one, so when I eventually add one I'll probably get a heat pump if it's not much more expensive than an air conditioner.

I'm going to go with an induction stove. I'm considering a heat pump dryer, but the one from Whirlpool seems to have quite a few bad reviews. I might wait for the next generation.

So far I've been trusting the energy guide label for water heaters, but I should figure out how to do the calculation myself.

robartsd

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Re: heat pump water heater
« Reply #36 on: December 26, 2017, 09:59:27 AM »
So far I've been trusting the energy guide label for water heaters, but I should figure out how to do the calculation myself.
The energy guide labels should indicate the rates used in the calculations. Adjusting the label values for your actual rates will help compare one unit to another (of course many areas have different electrical usage rates at different times of the day making this more difficult). If the units are similiar cost to you, then this is probably enough, but if the unit with lower operating costs is more expensive, you'd want to use an estimation of usage costs based on your own usage patterns to calculate the payoff period of investing in the more efficient unit.