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Tankless water heaters are terrible....

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There's a pressure relief valve and pipe. I just ran the condensate to that pipe

I suspect that technically that is not allowed since one of the intended uses for the pressure relief pipe is "show" when pressure relief valve is tripping. In my area the pressure relief has to run out somewhere visible. If you mix it in condensate then won't be able to tell why it is dripping. Of course practically speaking I'm sure it would work.

For the one I had installed a few months ago the condensate pipe just drops into sink that is next to it and it passed inspection. Originally my plumbers quoted me a new run to the outside because they were thinking classic acidic condensate from a gas burner. I was thinking the same thing before I remembered that this condensate didn't have that problem and we can just send it down the sink.
 
I don't know about your DIY skills, but if you are replacing an electric water heater, it's dead simple to install a HPWH. Just fasten the water intake and output flexible couplings at the top and attach the wire. I've done this myself.

That is a great point to make...although in my case, I was replacing a gas heater. I am pretty sure I read the installation instructions for an HPWH and felt overwhelmed, although my DIY skills are indeed poor so maybe it was just me...I don't remember the details.
 
This water heater makes some noise like a very small window AC unit. The byproduct is cold air so it nicely cools my garage which can get really hot in the summer. Outside or garage install is perfect. Inside your home you might not like the noise.
Yeah, inside the house it might be too noisy unless the room it's in is sound insulated from nearby rooms. And then you have to make sure that you vent that room. Mine is in my garage, right next to my living room. You can hear it through the wall/door (exterior-type door, so well sealed), but it's barely noticeable. Through the wall/door, it's like being in the same room as the refrigerator when running, so not objectionable.

That is a great point to make...although in my case, I was replacing a gas heater. I am pretty sure I read the installation instructions for an HPWH and felt overwhelmed, although my DIY skills are indeed poor so maybe it was just me...I don't remember the details.
It's really not that hard if you have basic plumbing and electrical skills (depending on what type of heater your old one is). I also opted to extend/reroute the lines for my Rheem HPHW, but honestly if you were trying to minimize the plumbing work, you could use PEX tubing which would have been a lot faster / easier than soldering a number of copper fittings.

I've had my 50 gallon Rheem for a year now (family of 4) and still keep it in heat pump only mode. In heat pump only mode, especially now that it's cooled off (about 65F in my garage right now, 75-80F in the summer), recovery times are definitely longer and back to back or long showers at high flow rates can cause you to run out of hot water. This is NOT a problem in energy saver mode, but energy usage goes up and I use the cold water as a indication that we should be taking shorter showers!

Energy usage for the last 12 months according to EcoNet is about 700 kWh. I estimate 6-8 therms/month on my old gas water heater (have a bit of gas house heating that's hard to separate out), but assuming about 7 therms/month, that's about 2500 kWh equivalent, or about 3.5x less energy in total. Efficiency would drop a bit more by using Energy Saver mode, but it's still a win. I would suggest that most people start off with that mode. I highly recommend the Rheem, would definitely buy again.
 
This is exciting. Basically starting next year in Seattle all new commercial and multi-family buildings including hotels will be required to heat their water with a heat pump.

Seattle Advances Energy Code Updates Aimed at Curbing Carbon Emissions


Needs to be a National Code. Pure resistance electric and gas water heaters really need to be phased out like incandescent bulbs. With economies of scale heat pump water heaters using CO2 as a refrigerant could probably drop into the ~$1k - $2k range.
 
We've had a 65 gallon Rheem hybrid heat pump water heater for nearly 2 years and, like Sawyer8888, it's been trouble-free and extremely efficient. Here is a house with a total area of 2550 square feet for a family of four. Two showers per person per day, a lot of dishwasher and laundry use with two boys, and a lot of sink use. Every year, we use roughly 1500 kWh.


I'd want to dispel a handful of myths that were mentioned earlier in this thread:
1) Slow recovery time: This would be true if heat pump boilers were not "hybrid," but they are all "hybrid" and include resistive heating. While the "heat pump" alone mode is the most efficient and should usually be set as the default, you can choose hybrid modes such as "energy saving" or "high demand" for more guests, or even force 100% resistive only "electric" mode and Check more
True, heat pump (hybrid) water heaters can't generate heat as quickly as tankless heaters, but this isn't a concern here or in most homes. The size of the water heater is crucial. In our situation, upgrading from a 50 gallon NG unit to a 65 gallon one provided us with more buffer space. Rheem produces More Details.
 
Those things in that article are gigantic! Serious McMansion stuff.

I haven't the space for something like that. My water heater is a small unit that hangs on a wall. I hope they make smaller ones that don't take up so much space. My NG use for cooking and water heating is 2 therms a month ($2.50), so running electric lines and switching to a heat pump wouldn't be remotely cost-effective. If I was designing the house over again, sure. Retrofitting now would be fantastically expensive. Do think about it though, the usual "if I were rich" sort of dreams.
 
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686FD86B-1802-4C34-9AA4-928A1CA78877.jpeg

Space heating and water heating account for nearly two thirds of U.S. home energy use
 
For those upgrading from NG->HPWH, suspect most will gain space as we did.

We replaced our 50G NG water heater a few years ago with a 65G HPWH. The larger storage capacity HPWH takes up less space as we were able to remove the elevated platform that is code for NG but not HPWHs:
  • Water heaters installed in residential garages shall be elevated on platforms so that the flame
    or burner is a minimum of 18 inches above the floor unless listed as a flammable vapor
    ignition resistant burner. (CPC 507.13)

Additionally, no flue on the HPWH, so now we have several feet of space above the water heater we can use for something else in the future.
 
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For those upgrading from NG->HPWH, suspect most will gain space as we did.

We replaced our 50G NG water heater a few years ago with a 65G HPWH. The larger storage capacity HPWH takes up less space as we were able to remove the elevated platform that is code for NG but not HPWHs:
  • Water heaters installed in residential garages shall be elevated on platforms so that the flame
    or burner is a minimum of 18 inches above the floor unless listed as a flammable vapor
    ignition resistant burner. (CPC 507.13)

Additionally, no flue on the HPWH, so now we have several feet of space above the water heater we can use for something else in the future.
Depends on the water heater, I suppose. Mine hangs on a wall, well off the floor, and measures 18 inches wide by 30 inches tall by 8 inches deep. Does have a five inch flue above it, however. I gather that this thread was created to dis on demand (tankless) water heaters and that's what mine is and why it is so small and uses so little NG.
 
Depends on the water heater, I suppose. Mine hangs on a wall, well off the floor, and measures 18 inches wide by 30 inches tall by 8 inches deep. Does have a five inch flue above it, however. I gather that this thread was created to dis on demand (tankless) water heaters and that's what mine is and why it is so small and uses so little NG.
Sounds like yours meets your needs and you use only 2 therms/ month for combined cooking and water heating. That's truly impressive. You are probably in the lowest 1 percentile for energy use in these categories, so A+ for low energy use.

Environmental benefits aside, for the large majority of Americans, though, a HPWH (new property install or upgrade) will probably pay for itself within a few years given EIA data above.
 
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