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High end tanks like that have much thicker insulation. HPWH are far more complicated mechanically. Lots to break on them. They also don't have the greatest COP. Better then resistive heat as long as they are in a conditioned space, but no where near the same $ cost compared to NG or even propane and oil. (unless you have ridiculous delivery fees)
My house heat is a coal boiler and i cant even beat $10 a month HW for a family of 4 with that. Gas or oil is certainly more costly than coal. Even cheap gas is more than coal and oil is 100% more. HP mode uses 550 watts vs 4500 watts in resistance mode.
 

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Avg US price per Therm of various fuels, YMMV

electricity $4.22
coal $3.00
gasoline $2.65
propane $2.53
oil $1.69
wood pellets $1.56
nat gas $0.95
 

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They seem to feel free to ask about anything, short of brain surgery. :D

Would an average DIY'er tackle repairing a tankless heater?
Maybe.

Should they?
I wouldn't, even with schematics, the source code for the computer, a whole bench full of test equipment, etc.

If I had the factory service manual in front of me, maybe, but these manuals sometimes call for test fixtures that are hard to get.

Industries do not want DIY'ers to succeed, it is money out of their pockets. :(

And some OEMs put booby traps into their devices to punish the plucky DIY'er. Who's to stop them?
We don't have their source code, we just follow their service procedure, and test what the manual says to check. The manual comes with the tankless. And hey have no booby traps for service.
 

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My whole Electric bill for hot water is only $120 a year with a HPWH. Not possible to have anywhere near $100 in standby loss. Plus it dehumidifies my bsmt for no extra cost. The 10 gallons of hot that is cooled by incoming water is also warming up the incoming water by the same amount so your have zero actual loss there,certainly not $100 of loss. IMO a superior hot water solution to either a regular electric or a tankless.
Were not comparing a heat pump water heater to a tanked electric resistance water heater. But a HPWH won't have nearly as much operating cost as a resistance one.

As far as the cold water being heated up by the loss of the hot water. Its still a loss, as you already paid to heat the water once. And your only getting 30 of the 40 gallons you had stored.
 

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natural gas $9.52 per thousand cubic feet
electricity average cost of electricity per kWh is $0.14
coal $71.54 per short ton
oil $2.35 per gallon
gasoline $3.18
wood pellets $5 per 40 pound bag
propane $2.30 per gallon
That would make electric cost $41.02 to equal gas using an 80% efficient unit at a cost of $11.90
 

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As far as the cold water being heated up by the loss of the hot water. Its still a loss, as you already paid to heat the water once. And your only getting 30 of the 40 gallons you had stored.
Your simply trading 10 gallons of hot and 10 gallon of cold for 20 gallons of warm. Not losing or gaining any energy. Your WH now only has to heat warm water to hot not ice cold water to hot.
 

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Your simply trading 10 gallons of hot and 10 gallon of cold for 20 gallons of warm. Not losing or gaining any energy. Your WH now only has to heat warm water to hot not ice cold water to hot.
The cold won't warm up enough to be considered warm.

Plus, your still only getting 30 gallons of hot water from storing 40 gallons of hot water.
 

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My house heat is a coal boiler and i cant even beat $10 a month HW for a family of 4 with that. Gas or oil is certainly more costly than coal. Even cheap gas is more than coal and oil is 100% more. HP mode uses 550 watts vs 4500 watts in resistance mode.
You shovel coal into your boiler? I've never actually seen one used in a house. They were all ripped out here long before I was born. Some of those same houses have switched to oil, HP, then to NG, each at the end of the useful life of the appliance since then. The closest I've seen in operation is a modern wood / oil combo boiler.

$10/ month is not to whole story. Pulling up the specs of a couple average HPWHs, they only have a COP of 1.5-2.5 depending on air temps. These models use a bit more power at 6-700w. They put the annual energy bill at $250-300 using 10.6 ¢/kWh, which is a bit unrealistic for the vast majority of consumers. That's using 3" polyethylene insulation on the tank. With all that, they still only get 5-10 gph on economy only mode. 20gph in hybrid mode. (with the electric elements on) My tank hits 130-180 gph. (enough for continuous hot water supply with a single water saving shower head, with an 85°f rise.) I really don't feel like having to space out short showers by hours.

Most comparisons that I can find don't include any delivery or tax rates per kWh, which can be very significant. I'm not sure of this site, but here's a reference anyways.

That's all excluding that the energyused to heat the water, above a COP of 1, has to come from somewhere. If you need to heat the space that the HPHW is in, then you need to include that in the energy cost as well to be fair.
 

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You shovel coal into your boiler? I've never actually seen one used in a house.
That's all excluding that the energy used to heat the water, above a COP of 1, has to come from somewhere. If you need to heat the space that the HPHW is in, then you need to include that in the energy cost as well to be fair.
No i dont shovel ,its all automatic. Automatic Coal boilers are fairly common here in Pa. I dont heat the space the water heater is in. And i never run out of hot water. At 12c KWH i save about $300 a yr over a regular WH so it paid for itself a long time ago. The new ones claim to save as much as $480 a year in electric cost. (possibly at a higher Kwh rate)
After using regular HW heaters of many years i have this HPWH for about 6 or 7 yrs. And when is dies ill get another one. It makes hot water exactly the same way your refrigerator makes cold air in reverse. In fact if they could somehow combine the 2 ,one of those functions would be free.
 

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No i dont shovel ,its all automatic. Automatic Coal boilers are fairly common here in Pa. I dont heat the space the water heater is in. And i never run out of hot water. At 12c KWH i save about $300 a yr over a regular WH so it paid for itself a long time ago. The new ones claim to save as much as $480 a year in electric cost. (possibly at a higher Kwh rate)
After using regular HW heaters of many years i have this HPWH for about 6 or 7 yrs. And when is dies ill get another one. It makes hot water exactly the same way your refrigerator makes cold air in reverse. In fact if they could somehow combine the 2 ,one of those functions would be free.
All of the HPWHs that I've seen still have electric resistive heaters in them, due to the very low heat recovery rates. People running out of hot water is very common for either HPWH or electric resistive HWHs. Since many people have to change their tank every 2-3 years, it wouldn't make sense for them. (they don't even use NG when it's available due to the higher replacement value)

You'd have a better chance at heat recovery from your ac than a refrigerator. More energy being moved. At the temp difference between the refrigerator and hot water, would have a COP far below 1. (resistive elements being more efficient) refrigerators already have very low COP. It just doesn't make sense.
 

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All of the HPWHs that I've seen still have electric resistive heaters in them, due to the very low heat recovery rates. People running out of hot water is very common for either HPWH or electric resistive HWHs. Since many people have to change their tank every 2-3 years, it wouldn't make sense for them. (they don't even use NG when it's available due to the higher replacement value)
If your WH only last 2-3 yrs you must have caustic water. The HPWH also has a 10 yr warranty. In hybrid mode its all but impossible to run out of hot water as they employ both heat pump and elements when needed. We do 2 loads of laundry a day and have 4 to 6 people living here taking showers as well as a dishwasher going. Never run out. They may no work well in your section of canada but they sure work great here in the US. If it didnt id have replaced it many yrs ago.
 

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In NY I use a tank type water heater because we never have a hot water shortage, they are cheaper than tankless, our house is plumbed for a tank so minimal work is needed to replace it, it is in the cellar so there is lots of room for it and any waste heat is ok during most of the year and there is little maintenance. I am not against tankless water heaters, though. We have a tankless in a vacation rental because it has 4 bedrooms and 3 bathrooms. Guests like to all shower and go out, so they never run out of hot water. If I had a bigger house and a larger family I might go tankless. If I lived in a hot climate and didn’t have natural gas, I would consider a heat pump water heater in the garage. It would efficiently heat water and discharge cold air into the garage. We have a tankless unit in our FL house because it is mounted outside on the exterior wall, we have natural gas, and the house has 4 bedroom and 4 bathrooms. What to use depends on your individual situation.
 
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The 50w or 75w my old WH put out is benefit or a drawback, depending if the heat it adds to the room is wanted.
At 65F outside, it's either one.
 

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the breakeven point for the annuity you are paying to the PoCo vs. the lump sum & install for a tankless
may be years away.
Or decades...
Which comes out to 1.79KWHs per day, and 53.79 KWHs per month. So around 90 to 100 bucks a year in stand by loss.
Maybe with an electric WH. With a NG tank, it would about $20 a year, assuming the standby loss numbers are accurate.

Replacing a NG tank with a NG tankless might be worthwhile - if you can change the vent yourself and your gas line is adequate. Replacing a NG tank with an electric tankless is a losing proposition money-wise - it's more expensive to buy and more expensive to run.
 

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If your WH only last 2-3 yrs you must have caustic water. The HPWH also has a 10 yr warranty. In hybrid mode its all but impossible to run out of hot water as they employ both heat pump and elements when needed. We do 2 loads of laundry a day and have 4 to 6 people living here taking showers as well as a dishwasher going. Never run out. They may no work well in your section of canada but they sure work great here in the US. If it didnt id have replaced it many yrs ago.
Rural communities can really struggle with their water quality. Sucks for them. Certain water conditions will void the warranty. It's part of the reason why you need to provide an address for warranty replacement.

A 30-40 gal, first hour rate, and less then 20 thereafter is pitiful and generates plenty of complaint business for me. If you're raised your tank temp to compensate, then you've killed the COP on the HP portion. When it's heating with the resistive heaters, it's certainly consuming plenty of electricity.
 

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A 30-40 gal, first hour rate, and less then 20 thereafter is pitiful and generates plenty of complaint business for me. If you're raised your tank temp to compensate, then you've killed the COP on the HP portion. When it's heating with the resistive heaters, it's certainly consuming plenty of electricity.
Not sure for mine but a new Rheems are 60 to 87 gallons first hour 40 to 80 gallon models. Looks like the smaller one has better recovery. Mine is a 50. Not sure how much i save not having to run a dehuimidifier anymore but they take a lot of juice as well. Between the 2 my electric bill went down an avg of $25 a month after i replaced regular WH with the HPWH.
 

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Not sure for mine but a new Rheems are 60 to 87 gallons first hour 40 to 80 gallon models. Looks like the smaller one has better recovery. Mine is a 50. Not sure how much i save not having to run a dehuimidifier anymore but they take a lot of juice as well. Between the 2 my electric bill went down an avg of $25 a month after i replaced regular WH with the HPWH.
That 26 gph is with the electric elements going full, (all 4500W,) right from the beginning. At that point, why not save on the tank and just wrap a standard electric tank to get the same insulation value. The insulation is a lot cheaper than the HP. In fact, the most expensive Navien DHW is cheaper, including with the union kit and venting.



At 3× the price, it'll take a long time to pay off that capital investment. With a dry, watersealed basement and proper airflow, you shouldn't need a Dehumidifier in the basement in the vast majority of locations.

Plus, those are 30A tanks. The average tank is 20-25A. You'd need to upgrade the breaker and line to retrofit it.

Then add the fact that 75 gal/first hour is still only 1¼ gpm, half the water consumption of a water saving head. That ends up only being 45 min of hot water. (32 min for the 40gal) So with 2-4 people taking consecutive showers, and the last person finishes with cold water. With a non water saving head, or multiple head setup, you have 16-7 min of hot water. (5-10 gpm respectively.) Definitely in angry user territory. Both cases requiring nearly 50 min before you've heated the whole 60 gal again. Tolerable with a single water saving head in a single shower. Outside of that, it'll very well be noticeable.

My 50gal condensing tank will go over 2 hours before running out of water on a single water saving shower head. If I had picked up the 60 gal instead it would have been 2½ hours with the same head. 20 min at 5 gpm. Of course the Navien would run forever like that. So if you have 2 showers in the house and people tend to take showers at the same time, along with other activities that consume hot water at the same time, electric tanks really aren't going to cut it.
 

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With a tank or a tankless, the operational cost of natural gas will beat electric resistance heating pretty much every time. Operational cost of heat pump water heaters compared to natural gas apparently can go either way, depending on the gas and electricity prices in your location. The cost to get the heat pump system installed is much higher, though. Seems like in most cases it would only be worthwhile if the heat pump is one of the complete systems, which replaces the WH, furnace and A/C, although the chances of needing all 3 at the same times seems fairly unlikely.
 

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The gas tankless are on (guessing) 90% of the homes in Japan. Only recently because of government incentives and small subsidies to become more eco minded homes have switched to electric tank water heaters usually kept outside. We’ve bough a house and remodeling it and switched to tankless and LP gas with tanks. I tore apart the tank unit and used some of the outside metal for a oven exhaust hood and the big cylinder I’m thinking of turning it into a smoker, to keep the whole eco thing going ya know.
 

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Years ago, back in 2008, I had a house in Norther NY (NY, VT, Qc border). House had had an apt at one time, so had two 40-gal gas fired water heaters. Bother were old, and quite "crudded up". My father-in-law, was in the plumbing business and was retiring. He got me a nice Rinaii gas fired instantaneous heater to replace the two tanks. Installation was easy. Only issue was the cold slug of water when using for showers, etc, as the heater was in an unheated basement (fyi, at time of purchase of 50's house in the fall of 2006, no pipes in basement were insulated). What I did to solve the issue was install about 30' of pipe with an inline circulator that had a timer built in. I would set the pump to come on in the morning and again in the evening and never had another issue.

At my previous home, in PA, the house had an 80 gal elec tank style heater. The tank was crudded up very bad and at time of replacement, we could not get another 80, could not get a 60, could not even get a 50 gal tank. Ended up with a 40 gallon tank. I was told at the time that the govt was cracking down on "inefficiencies". I could still order the larger tanks from Canada, but nothing in the states other than the 40 gal.

We just moved to Virginia and every new house here has a Rinaii wall mounted unit. Had I been around during the install, I would have made provisions to put in a bypass loop on a timer so that we did not waste so much water waiting for heat up.
 
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