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Heat Pump water Heaters

I've been running a GE Geospring heat pump water heater for 10 years now...trouble free. I do have a water softener and believe that makes all the difference in the world as far as longevity goes.
If yours is a salt based softener system it will actually speed up deterioration of the anodes, etc. The HO Smith HP unit manual specifically calls this out for increased frequency anode inspections.
 
Hopefully better than the 900 model 50g unit. Same as my friend, you have little to lose at THAT PRICE. HOWEVER - here's a review snip and I'll summarize, having read the reviews - half loved it, until the compressor crapped out repeatedly for the other 50% within 6-24 months.
Yea I saw the reviews also. But at this price I can just run it in straight electric mode if I lose the heat pump. 10 year parts warranty but I figure since it was a DIY installation they would find a way to not honor it.
 
wtf how do they even spring a leak lmao
You'd think these companies can make a container to hold water by now

yea ao smith & rheem are basically the same quality wise. but that's nice to know about the rheem warranty
Steel rusts.
 
If yours is a salt based softener system it will actually speed up deterioration of the anodes, etc. The HO Smith HP unit manual specifically calls this out for increased frequency anode inspections.
Yeah, GE says the anode will be "consumed more rapidly with artificially softened water". I need to check its condition. Still better than turning the whole tank in to one big block of stone.
 
I bought a 50gal Rheemes Hybrid Water Heater for ~$700 + ~$300 instant rebate at Home Depot in 2019 - e.g. cost me ~$400 out of pocket.

I cannot believe the current prices - seem way out of wack or did dumb me just happen to get the deal of a century in 2019?!? Not sure what's happening these days.
 
Hot water tanks in the UK are copper, I never heard of one leaking, ever.
The copper hot water pipe under my slab started leaking. Copper corrodes though it was 50+ years old. I've had a couple of three water tanks crack and leak. One destroyed a wall. I'm skeptical, but perhaps it's softer/more elastic/thicker?
 
If yours is a salt based softener system it will actually speed up deterioration of the anodes, etc. The HO Smith HP unit manual specifically calls this out for increased frequency anode inspections.
Back when I had one, my salt system did not run thru the HWH, it was cold water only. Interesting..
 
30% federal tax credit for HPWH.
30% off $1699 is still $1,189. That's a far cry from the $300 I paid (after instant credits) in 2019 + I got something off my taxes. Either the price in 2019 was insanely low or someone is jacking up the price here in 2024.

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With a heat pump water heater in heat pump mode, it will take longer than 20 to 30 minutes for hot water. You could use the electric element for faster recovery, if you have the power to do so.
Ja, this is why I don't have one.
Some people don't want smart devices. Some find value in them. I'm not interested in home automation. But I do see some value in the ability to change water heater temp, turn it on/off, turn on devices with smart plugs and run my heat pump mini splits remotely.
Not knockin ya, well, maybe jerkin the chain a little, but I wonder how long you will find that interesting enough to get the roi. (y)
I can manage my system and loads according to my choice.
Of course, I've found there is often diminishing interest as time goes on, but there is always some level of control we will always want to be able to excercise at will. If there were not people like you pushing the edge of the envelope, we wouldn't get all the fun toys to play with!
Last year we used less than 3% of total Kwh for the house from the grid. Meanwhile, we increased usage by about 15% by switching to heat pump tech for both heating and cooling.
That last few percent is always the most troublesome. Todays heat pumps are downright stunning for HVAC. I've mentioned in a few other threads, I'd go all electric if I went completely off-grid even in a northern area, and just have some backup via propane or wood. I just wouldn't want to crimp my lifestyle to get that 3%. I can't wait for summer, I added battery last fall, and made some overall improvements, my only grid usage the last 2 months was ~ $0.50 during a firmware upgrade. Pretty sure 60KWH is not going to make it thru the 100 degree nights. Bottom line is always what does it take to be grid-free.
I expect to see an increase again in the next year as we moved to the heat pump water heater and added another heat pump mini split. My idea is to generate as much as I can and use it when I can but not exceed system generation and use power from the grid. Some might not be interested in maximizing yield and solar power usage. That is fine.
You are down to shaving basis points, ROI gets worse and worse as you invest more money, so you've opted for heavier handed management to accomplish the goal. Nothing wrong with that. I think we are all about production and usage, just more around what we are willing to do to get there. I'm awed you are willing to get this creative! I'm sure it's something that brings you pleasure and satisfaction to see it come to fruition. That is what traveling thru life is all about! If you ain't having any fun why bother?
 
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For those of you with HPWH's already, using it in heat-pump only mode how do you find the recovery time? Our shower is a water hog-- something like 12 gallons per minute. Usually showers are very short (<3 minutes of running water), but some days they go longer and back-to-back showers are common.

Our current water heater setup is solar with a total of 240 gallons of storage, resistance backup heat on one of the two tanks that gets used maybe 10 days per year. (The house was built as an AirBnB and could hold 20 surfers.)

If I went with a HPWH the solar HW would need to go; I can fit 3.2kW of PV panels in the same space easily.
 
Running is 400 watts. Assuming 3x efficiency, that is an effective 1,200 watts. About 1/4 of a 5,000 watt resistance heating element. Mine ran almost all day (7 hours?) To do the initial heating of the 50 gal tank.

If I do the calculation right, it is about 7 gal/hrs to raise 60 degrees. Something like 50-60 gal first hour delivery rate. Heat to 145, and use mixing valve to reduce to 120.

It does have resistive heating element for faster heating.
 
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30% off $1699 is still $1,189. That's a far cry from the $300 I paid (after instant credits) in 2019 + I got something off my taxes. Either the price in 2019 was insanely low or someone is jacking up the price here in 2024.

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You are forgetting inflation.

My business management system has a screen that pops up when entering in a vendor PO and invoice for a part number that was sold here before. Most items have increased by 45% since 2019, easily over 7% per year compounded.

The government lies about inflation. I finally figured out the true % increase per Kwh the utility is enacting over this year and next. The second year is compounded off the first year increase. It comes to 26% increase over those 2 years from last year.

$700 x 8% compounded yearly =$1028.53

$700 x 1.45 = $1015

That is the true rate of inflation since 2019.
 
For those of you with HPWH's already, using it in heat-pump only mode how do you find the recovery time? Our shower is a water hog-- something like 12 gallons per minute. Usually showers are very short (<3 minutes of running water), but some days they go longer and back-to-back showers are common.

Our current water heater setup is solar with a total of 240 gallons of storage, resistance backup heat on one of the two tanks that gets used maybe 10 days per year. (The house was built as an AirBnB and could hold 20 surfers.)

If I went with a HPWH the solar HW would need to go; I can fit 3.2kW of PV panels in the same space easily.
Keep your solar water heater until it fails. Nothing is cheaper than something that is already paid for and running. 240 gallons is nice size, using a calculator for heat storage of 90°F to 130°F comes to about 23.5 Kwh. Heating water coming out of the ground at 55°F to 130°F is 44Kwh.

I figure 8 hours to fully warm up 50 gallon HPWH from about 55°F to 130°F. Compressor running is around 400W. Yes, I know the math doesn't seem correct with a COP of 3 to 4. It will depend on ambient temp where the water heater is located, COP is higher at lower water temp and higher room temp at the start due to Delta T. As the water heats up in the tank and room temp drops, the Delta T is lower and COP will drop.
 
Has anyone tried the AOSmith heat pump water heaters?
I've had one for a couple of years now. I run it solely in the heat pump mode, have never had to use the coils. Don't have details, but my electric use is down. No issues to date.

It's my understanding that AO Smith just puts their label on the heater, it's not "theirs".
 
They do, stainless and abs.

Not cheap, I bought a lifetime plastic tank water heater for a rental, about double the price.
I wouldn't want ABS for my water
I have had a PTF...E? 300 gal tank for like 15 or 20 years and it works fine, cost $200.

Hot water tanks in the UK are copper, I never heard of one leaking, ever.
yep, pretty nice
 
PTFE: PFAS

PFAS is known as one of the forever chemicals. EPA has been shutting down farms that applied sewage sludge containing PFAS.
I live in the epicenter of the PFAS problem, in rural Maine. This whole issue with PFAS started (basically was discovered) here because years ago the state encouraged farmers to take sludge as a great source of fertilizer. It isn't really the US EPA that's "shutting down" farms, so much as some of the farmers themselves (people love to blame the govt, but in this case, they're actually a little bit behind on the issue). In fact, EPA only recently revised their PFAS limits (much lower). PFAS contamination will likely be a much bigger problem all over the US in coming years, as the effects of PFAS chemicals are just becoming more widely known. As you note, fields that have been fertilized with sludge are the big problem, and there are a lot of them.
 
A tank type water heater is an energy storage device, just like any battery. A HPWH is a smart appliance that can be programmed with an app or home energy management system to run only at times of cheap electricity or excess solar production. I originally wanted to install a dump load for excess electricity available from PV and decided to buy a hybrid HPWH instead of heating element only water heater.

The HPWH is so efficient it really isn't a dump load, I just let it run all the time. Come winter, with the HPWH ahead of the propane water heater, I can use the propane during extended periods of low PV production.
Yea our elec rate all in is about .12 to .13 kWh.

I also have an off grid cabin and anything heat related is propane.
 
PTFE: PFAS

PFAS is known as one of the forever chemicals. EPA has been shutting down farms that applied sewage sludge containing PFAS.
luckily that isn't PTF/E
Looks like some relation to teflon (PTFE) for your PFAS though

and my jug is PET / PETG lmao damn acronyms..
 
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I'm thinking that I will leave my propane water heater as is and install a modified electric water heater as a preheater. I would use the existing water heater thermostat to control the coil of a high voltage DC contactor fed with either 116VDC @1,200W or 155VDC @ 1,600W from 3 or 4 panels. Will select optimal heater element ohms to match the PV voltage. By running the dishwasher and washing machine in the afternoon and evening showers the propane heater would seldom fire. 1,600W X 3.41= 5,456BTUH or about 10GPH of water heated 65degF (60-125F), so by noon or 1PM plenty of water all afternoon. Not counting the panels (I have extra) or electric water heater (free or Craigslist bargain) it might cost a couple of hundred dollars which equals something like buying 50 gallons of propane.
 
Question for folks about HPWH with the heating element (non heat pump / hybrid). I was planning on using the "smart load" / excess-power-dump feature of my all-in-one inverter to put excess power into the hot water. But that means that sometimes (often) the hot water heater might want to use the resistor but the inverter won't be powering it. Does this cause a problem / fault?

Like at 0300 in the morning if the heater is looking to run the resistor it won't be powered on, but it most likely will at 1400 the next afternoon.

I know the Rheems want to see power on that resistor at startup just as a systems check, that should be easy enough because I just can boot up the Rheem when there's excess solar.

Just curious if any of you have played with that.
 
My opinion, HPWH is a great concept, however so far, the physical executions are short of wonderful. I will wait for the equipment designs to mature and prices to drop before purchasing.
If the current regime has their way, you'll be forced to buy one if your tank fails and you need a new tank, whether things are mature or not.
Yes, they're coming for our water heaters now :rolleyes:
 
Question for folks about HPWH with the heating element (non heat pump / hybrid). I was planning on using the "smart load" / excess-power-dump feature of my all-in-one inverter to put excess power into the hot water. But that means that sometimes (often) the hot water heater might want to use the resistor but the inverter won't be powering it. Does this cause a problem / fault?

Like at 0300 in the morning if the heater is looking to run the resistor it won't be powered on, but it most likely will at 1400 the next afternoon.

I know the Rheems want to see power on that resistor at startup just as a systems check, that should be easy enough because I just can boot up the Rheem when there's excess solar.

Just curious if any of you have played with that.
Smart water heaters can be programmed for time on/off. If you don't want the water heater to run during the night, you can program it to not run. Do not cut power to the unit, it isn't needed. Just program it to run during the day.

I turn my HPWH off at night when there is bad weather for several days. Doesn't affect the temp if you want to take a shower in the morning but I do have the 50 gallon propane in series so 100 gallons of hot water. I do have a thermostatic shower valve.

After owning a hybrid heat pump water heater, I would not choose any other electric water heater for my personal use There is the choice of heat pump and element (high demand) or only heat pump. Plus Eco mode.
 

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