Electric water heater: OK to turn it off?
It's August 1, the day the new electric rates begin. This month I'm going to experiment with ways to reduce water and electricity usage.
Electric water heater: I need very little hot water. In the summer cold showers would be OK. For washing dishes I can heat water on the stove. Laundry doesn't really require hot water. So I'm paying a lot to keep the water hot in the tank, but I get little return on that investment. I believe my water heater is set at 120 degrees. I can't set it lower due to the risk of Legionnaire's disease (in fact on study found that the bacteria can grow at 136 degrees). Plan B: Turn off the hot water heater altogether so that cold water is drawn directly from the town water supply. Questions: (1) How exactly would I do that? (2) Will the standing water in the water heater cause any damage to the heater or other problems? (3) When (if) I turn the water heater on in the winter, how would I ensure the safety of the water in the tank? |
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2) No. Full of water, hot or cold, no difference. 3) I'm not sure on that one. I'm of the opinion that you use cold water for potable water, meaning drinking and cooking and brushing teeth. Use hot for showers and dishwashing etc. Keep in mind your cold water may not be great to start with, never know until you test it. Having said all this, I don't recommend what you are thinking of trying. Warming a few pots of water on the stove will use more energy than full days of the hot water heater. A good quality, well insulated hot water heater doesn't use much energy to keep water up to temp, the energy use is when you use hot water and it has to bring cold up to temp. So if it were me, I'd minimize hot water use with cooler showers etc. but leave the hot water heater on. |
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I'm one person, so washing the dishes takes at most a small kettle of hot water mixed with cold. Literally two minutes on the stove for the whole day's dishes. That's really the only hot water I need in the summer. |
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I hear what you are saying about not using much water. I'd still leave it on. |
Many people place them on timers, so that they only heat up about an hour before they need the water and then shut off for the day.
Shutting it off is as simple as flipping the breaker. |
Water heaters with cold water are a total gamble with bacteria.
In fact, most new ones come with "vacation modes" and manuals that say not to use it. Also, the on-off cycles may be more damaging in the long-run. You're starting to get into the "penny-wise, pound foolish" territory. Sent from my SM-G990U1 using Tapatalk |
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If the valves are closed, why would there be air in the pipes? The pipes would be under pressure from the town water main, no? |
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By the way, I could get hot water from the furnace---I mean boiler---in the winter, but I'm not going to do that at $8 a gallon for oil. I'm hoping to minimally use the furnace this year. |
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It runs as long as it takes within 5 to 6 am to reach 120 degrees. My whole house electric runs around 60.00 in the summer and 80.00 in the winter. Also included is an electric stove and a clothes dryer I use twice a week or so and all lights are LED.
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I'm with the NH Electric Coop and I expect with the new rates my bill will go to 80.00 in the summer and 100.00 in the winter.
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I run an energy star window AC maybe a half dozen times a summer, my house is in the shade so it gets in the 90s only a few times a summer. I like the heat I'm old......lol
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You can't (shouldn't) draw water from the tank unless it's heated to minimum 120 degrees to avoid Legionnaire's bacteria. Thus water should not be drawn from a cold tank. Thus the tank would need to be completely closed off from the household pipes, no? The presence of Legionnaire's bacteria in rain barrels would also limit the use of that water. Apparently even flushing the toilet with those bacteria present is unsafe. This is all new to me. Sounds important. |
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I think a water heater blanket would be a better idea. They are cheap and will reduce heat loss to a negligible amount.
If you also insulate your pipes then the standby loss will be low, and you are only paying to heat the water you use. As fuel prices go up the sensible answer is more insulation, including walls, windows and attic. |
Why not just convert to an "on demand tankless hot water system" which will run only when the hot water is actually called for?
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An electric version may need a panel and service upgrade.
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#2. No #3. As long as you let the water heat up fully before using you should be OK. Dan |
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If you keep your WH on a timer once a day to bring the temp up, the only savings would be temp. maintenance power which, as others alluded to, is not much at all. If it's off for a while, however, then you're definitely going to save money (minus the costs for heating cleaning water). Doing some research, it looks like as long as you heat the tank up to the right temp before using it after it's been cool for a while, it should be safe. I might still use the "hot" periodically just to get some fresh water through there, but what I would NOT do is get into shutoff valves—if by chance the heater runs without enough water, your WH element is junk. I'd be interested to know how long you have to have it off before noticing a decent savings. Sent from my SM-G990U1 using Tapatalk |
A more reasonable approach would be to replace your water heater with a smaller capacity unit so that you are not heating so much water. Add a timer so that the heater is only heating water when are awake and you might eliminate 100 hours of heater run time in a month.
Depending on where your water heater is located, the heat loss (other than in summer time) may not be as much of an issue as you think. If it's in a part of the house that you heat anyway, then the heat loss from the water heater is offsetting runtime from your furnace. Granted it may not be a 1:1 factor, but it also might not be large enough to be a major factor. |
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If that rate is 20 cents, then an hour of operation is 90 cents, for example. Of course it's not running the whole time, but if you can eliminate 2 hours of heater run time per day that can add up to $54.00/month, or less than $2/day. |
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The same thing applies to heating/cooling homes: that sometimes it's cheaper to keep them at one temp rather than have to cool down/warm up a warmer/cooler house. The calculations, of course, depend directly on how long the appliance would not be used, which is why maybe vacation mode—7 days off/the whole summer for Sailin—may actually work *if* bacteria's not an issue if warmed back up before use. Sent from my SM-G990U1 using Tapatalk |
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Under what circumstances would the water heater lose water? Does it depend on pressure from the town water inlet? Like when the town water pipe freezes, the water in the boiler backflows? That has happened to me twice (frozen pipe at the road and cracked water main down the street). Scary. |
Legionnaire's disease
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I thought it was spread through HVAC systems and was caused by standing water in the vents somewhere,,, Has there been some newer discovery I may have missed? I have a friend who barely survived this and to date we still dont know were he got it, so I have a vested interest in this. Thanks for any new insight. |
You should only draw from the water heater if the hot valve is open in the shower or faucet.
If you do open the hot side, that should flush the system enough to keep the bacteria count from exploding. The only real value to that is that well water is cold, and the tank would slowly warm to ambient temperature without the use of electricity by drawing heat from the ambient air. So the tank water would be warmer than the well water. |
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If you had a shutoff after the water heater, you'd be fine. I was mostly referring to one before, which would prevent the water heater from filling if any were lost. Just not worth it given the potential damage to the tank. It sounds like if you're willing to shut it off for a while with a shutoff to keep the water heater water from mixing with the straight cold you might save a few bucks. I'd really like to know if it's worth all the rigmarole, though, after calculating costs to heat from cold, heat cleaning water, and always cold showers. Sent from my SM-G990U1 using Tapatalk |
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Quote from a report cited in that article: "A minimum storage temperature of 131 F is essential to prevent the spread of Legionnaires’ disease (131 F is the temperature at which Legionella begins to die). To assure a safety factor, the minimum storage temperature should be 135 F." CDC: "Legionella grows best within a certain temperature range (77°F-113°F). To keep water outside the range for Legionella growth, it is important to keep cold water cold and keep hot water hot." Empirical study: "L. pneumophila still persisted up to 58 °C [136F], with evidence that it was growing under the conditions of this study. Further, exposure to 51°C [124] water in a low-use tap appeared to optimally select for L. pneumophila (e.g., 125 times greater numbers than in high-use taps)." So I was mistaken in my statement that 110 degrees is safe. Numerous websites cite that figure as safe, including some government energy conservation sites, without giving evidence. |
If you shut the power to the tank down... the tank should not in any realistic condition get to an internal water temp of 77F.
When you turn it back on... a setting of 140F, and letting the taps run a bit should remove any concerns... as the water will not truly be stored - just not heated by the electric elements. The mixing valve should easily allow the 140F to be lowered to were you feel comfortable... and can be further adjusted by the faucet. At that time, heat lost by the tank to the surrounding air would just be space heating where the tank was located. |
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Interesting this information is not more widely communicated. Begs the question why,,, |
Some part of this discussion doesn't make sense to me. I think from the reading the issue is that water that is warm, but not hot enough, can grow the bacteria. That is not what you are talking about. You are shutting down the heater completely.
How could cold water flowing through copper coils in a hot water heater be more "dangerous" than cold water flowing through copper pipes to your cold water faucets? |
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At best, the piping leading to the tankless sitting long enough might reach ambient temperature... so a warm period might make it to the lower threshold... but once being heated, the bacteria would die. |
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A tankless is not inexpensive...
And many times requires a panel and service upgrade. So the output of capital most likely would eat up much of the savings. |
I'd just turn off the breaker to the water heater if you don't feel you have a use for hot water. Leave the valves open to and from the tank. If you close them the hot water taps in the house won't work without a plumbing bypass. Leaving them open will introduce fresh water into the tank when you open the hot water taps. You say you're on town water. Good chance the water is tested for bacteria and chlorinated if needed. There's a lot of standing drinkable water in pipes and tanks long before it gets to your house, most of it at 50 or so degrees. I wouldn't worry about storing 40 gallons in a tank for a short period.
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It takes up far less space than a tank style, and has an endless capacity when you need it. And the biggest plus of all, no tank to fail! And after having had several failures over the years, one that made a bit of a mess and ruined some stored paper items, this was a big bonus for me. Yes it might be double the price initially, but worth much more in the long run, well so far anyway! Dont think I'll ever be going back to a tank style again, and if what I am reading here is correct, it will keep me out of trouble for exposure to Legionnaire's disease, so add that to the plus column. |
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I looked at electric tankless water heaters a while ago. One thing that was recurring in all the articles I read was that tankless electric wasn’t recommended in the northeast due to ambient ground water temperatures (i.e., you couldn’t heat the colder water to a high enough temperature as it passed thru the system.). Has this changed?
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I can set mine at any temp and yes it gets plenty hot, once set it at 140 to see how we might like that and it was scalding! Now I run off city water, so I have no idea how that impacts the temp vs a very deep well, but I would think the deeper you go the warmer it is??? Any deep well owners that can tell us what your cold water temp is? Im a very long way from our treatment plant and our water can be pretty cold when it gets to me,,, |
Not a problem
An organization I belong to has a kitchen and we use a propane fired Navion tankless hot water heater. Our water source is an artesian well. The unit is in a utility area connected to the building and has one 6 ft long FHW heater register to keep that room warm. The bigger is also located in that area. When the building is not in use, the thermostat in that zone is set at 50.
When we do have a meal, once or twice a month usually, we do not notice any difference in the hot water temperature summer or winter. Nor do we notice a difference in how long it takes for the hot water to deliver the hot water. We do use a circulator to keep the water at a constant temperature when we are running the commercial dishwasher. Never have measured the cold water temp, but it's plenty cold. Dave |
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I've not heard good things at all with those, but you've been happy? Sent from my SM-G990U1 using Tapatalk |
Motivated by Sailin's "frugality," I decided to try putting my water heater's vacation mode on (60) while we're away the next week and while away the last two weeks of August.
In addition, most info I found says to set the central AC thermostat to 85 while away, so I'll try that as well—we usually just bumped that up from 72 to 75. I subscribed to Direct Energy this AM for my provider, which will limit my increase to $.165 vs. the $.225 Eversource jumps to this month. It looks like they had a $.12/.13 deal a couple weeks ago for a bit, but I missed that. Either way, it cuts the increase in half. Sent from my SM-G990U1 using Tapatalk |
I'd leave the hot water tank hooked up and just take cold showers. Have the hot water when you need it. You'll save almost as much money.
You keep asking for ways to lower your bill, but no details as to what is using the power. Some detail would be good. You did say you run dehumidifiers, which I do too. I just had a guy in here who saw the dehumidifier I'm using and told me to get an April aire unit. So I looked it up, an 80 pint a day April aire unit draws about 5 amps. The unit I'm using now draws 7.6 amps and is only rated at 40 pints. So in a perfect world the April aire would run half the time of my 40 pint unit and use only 2/3s the power while it is running half the time. Those are the things to look at. Another might be your fridge or freezer. If those are older a new one may save money. |
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Never heard of an electric tankless, I dont doubt they make one, but thats not what we have. |
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https://www.homedepot.com/p/Frigidai...547389#overlay (Of course, there are many complaints that MOST air conditioners and dehumidifiers only last two or three years these days.) |
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A shallow well (dug well) will actually have a higher temperature as it will approach ambient if not insulated. |
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I had it set to "comfort" mode, but it seemed to run too often and was very dry, so I set it to 60 percent. One common complaint about these units is that the moisture sensor is close to the water path, which throws off the actual reading. I'll see how 60 really performs and go from there. Sent from my SM-G990U1 using Tapatalk |
They do make them
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Dave |
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https://uploads.tapatalk-cdn.com/202...20859db034.jpg Sent from my SM-G990U1 using Tapatalk |
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They actually have great speed and efficiency.
But they require an amount of power that generally results in a service and panel upgrade. |
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The long-term reliability of electric on-demands was also reportedly lower, which meant the lifespan was shorter. Things certainly may have changed. Point-of-use electric on-demands were usually rated much higher, but that opened a different can of worms in terms of install costs, multiple units, etc. Sent from my SM-G990U1 using Tapatalk |
The heat is instant... why we call them ''on-demand''.
The gallons per minute that they can deliver is based on the temperature rise needed and the wattage of the appliance. While this link shows ''up to'' gpm; in general, for our area using well water would require the two bigger models for most homes... and if you undersize... you deal with it; while if you oversize... the unit just costs a bit more rather than take a lot more energy as the internals make up the difference. https://www.amazon.com/Rheem-Tankles...1MR7Z39V&psc=1 At the bottom comparison, you would see the 18 and 24. The data on the package is much more specific as to flow rate based on the required rise in temperature. Both would likely need a service and panel upgrade. I doubt when compared to a tank water heater that they would have a shorter lifespan or more energy consumption based on equal usage. It is just not the way that I would go. The cost of removing a functioning water heater, possibly moving it to a new location, and the upgrades would take quite some time to recoup when only the standby loss is taken into consideration. A simple time, or shutting of the breaker for longer periods, would cost less and create a large percentage drop in the standby power usage. |
I don't understand why running the hot water heater for a few hours a day on a timer or switch saves much, if any, energy.
Leave it on, and it maintains the temp you have it set for. Temp drops a bit and it comes on, in a 2 element unit (many are) only one element comes on. Turn it off for 12 hours and turn it back on, you are asking it to heat water from whatever it has dropped to back up to temp, using a longer run of the element and likely kicking in the 2nd element. And finally, if you use some of the hot water when the heater is turned off, you are later heating from room temp to set temp since you pulled much of the residual heat out by using the water. I'm not following the logic. I still say, make sure it is well insulated, and leave it on. JMO. |
For two reasons... she is talking about shutting it down for the season, not a few hours.
And secondly... when cold water is pumped into a tank and allowed to set... it will draw ambient heat from the room (the one you are trying to cool) and warm up to the point of reaching ambient temperature. Since the heating elements would be shut down for months... and the tank would gain heat while cooling the space... she gets water at maybe 70F without any cost to her... while also losing heat in the space. |
Thanks for that explanation John. I guess I get it with the complete shut down, but multiple people have talked about switches and timers that run the heater for a period of time each day and I guess I question the real savings of that. I admit I get mixed up between this thread and the "substantially reduce" thread so maybe it was mentioned in the other thread.
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Timers work in a different way.
It basically takes the same amount of energy to heat X number of gallons quickly, but at various times of the day, using the tankless systems... as it does to heat the same number of gallons slowly using the tank systems. The tanks systems must maintain the temp through extra standby usage; but if used all at once the difference between tank and tankless would be meaningless. The tankless version just allows more flexibility in the timing of the use. While the timer tank version has to be used when ready and not allowed to set. |
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Update: I meditated on the whole question of the water heater while taking a cold shower the other night. Brrrrr. Why are we so far behind the Europeans? 45 years ago I visited friends in Germany. They had a small box on the wall over the kitchen sink that provided hot water in a minute or two with the flip of a switch. They were amazed that I had never seen this before. I had to say, "Oh, in the U.S. we prefer to heat 50 gallons of water to wash the dishes and keep the water hot all day just in case." |
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What you're referring to in Germany absolutely exists in America—point of service water heaters—but I think American homes typically have more rooms with water than European (multiple bathrooms, washrooms, etc.). Sent from my SM-G990U1 using Tapatalk |
Propane tankless.
We have had them in the camper trailer since the 70s... maybe before. |
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USA vs the World
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We now know them as on demand heaters. They worked well with the knowledge of their "short comings ". Just couldn't take a half hour "aaahhhhhhhhhhh" shower. Most of them, as I understand it, were electric units. Dave |
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50-gallon water heaters are from the era when we believed that bigger is better and everything in our daily life must be super convenient and always at hand. I don't think we can afford that any more, financially or environmentally. I had a 53-gallon water heater installed only because (a) I didn't want to turn on the oil boiler in the summer to take a shower and (b) I knew that a 10-gallon heater would impact the resale value of the house. I could easily live happily with two gallons of hot water per day, mixed with cold. Surely there is a more efficient way to obtain that than a 24/7 53-gallon water heater! Hence my original post! For the life of me I still don't clearly see the solution in all that has been said in this thread.
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If you don't want to lay out money and make changes...
The easiest thing to do is just shut off the breaker. |
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EDIT: Woops, I think I meant to say "under sink water heater." |
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I see no down side and on the plus side, there is energy savings to be had, no tank to rust out, and no volume of standing water to grow bacteria. Some argue they cost more, but I dont think I paid more than if I bought a good brand/model of tank style heater. Take a look! Good luck. https://www.rinnai.us/residential/ta...-water-heaters |
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I am not a plumber and don’t know much about these and all I can say is I love mine and wouldn’t be without it. Here is a couple pics of it and the spec sheet on the side… Dan |
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Electric or propane? |
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Rheem has good ones.
I think you may be able to find them at one of the two Big Boxes. Just determine the size that you need, because too large will need a panel and service upgrade. We have quite a few of those going on in the Bristol area... and the pvc conduit is getting tricky to supply. |
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Update
At this point I've had the water heater turned off at the breaker for the past month. My August kWh usage was 34% lower than August last year with a combination of strategies.
Yesterday I closed the hot and cold valves on the water heater to make sure I'm not bathing with water from the heater due to the risk of bacteria. I'm drawing cold water from the town supply for bathing. Q1: My handyman says I should drain the water heater at this point to avoid mold etc. growing in it and also rust. Is he correct? Q2: Would the simplest solution be a well-insulated 10-gallon tank placed next to the 53-gallon tank? That way the next owner of the house could use the larger tank if they prefer, while I would not use the large tank from this point forward. |
Q1. What would the mold be eating? It shouldn't increase rust.
But if you aren't going to use it for a long period of time, draining it would be best... and shouldn't be that hard. Q2. You could. I remember when my grandmother would fill the tub about quarter/half way and then poor water from the kettle heated on the wood stove to warm it up. Since I prefer showers now... that is a bit harder to do. |
"Working" with Water Heaters...
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Back when I had 120-v water heaters, I put a household timer on them to save on excessive heating. It doesn't need to be really hot to be useful. One was 40-gallon, the other was 90. (!) Speaking of timers, take two $8 household timers--plugged together--to operate an irrigation/utility pump one hour a week from a lake (or cistern). Set one timer to go on for three hours, the second to operate one hour. Using this technique, you don't have to be present at the lake to water your plants. As to the number of days and hours, YMMV. Insurance-based water heater "take-outs" will help to economize. This being hurricane season, advertise "WTB" on Craigslist. I sold two to a desperate contractor who had a "tent city" of volunteer electricians with no hot water. I should add that mold is suspect in peripheral neuropathy, a nerve condition experienced by ~15% of Americans. |
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Trying to Make The Best of It...
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Days later, when the plumber replaced it, it was put out by the curb. Looking at the now-exposed wire connections, I realized that the heater was still good. :o As a backup, I'd previously purchased a 20-gallon, 120-V, water heater for $50. Small, it may have been smaller than 20-gallon. :confused: Those two "take-outs" I sold to the above contractor for $150. (Explaining all that I knew). So, I was "ahead"...sorta... :o |
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20->30 mins is more reasonable. |
When Shutting Off the Breaker, Observe...
Use the left (hot, red) faucet frequently to avoid "stale" water residing in the "shut-off-breaker" tank. (Although I don't think this is a real problem--even with lake water). Of course, there is no tank involved in the right (cold, blue) faucet.
Note, however, the left (hot, red) side is likely to have a taste of magnesium--or whatever anode is installed in the tank--so drinking from the left (hot, red) side might be objectionable. And, yes, town water ultimately feeds both faucets. (Or both of the red and blue sides of single faucets) Quote:
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My Myson 325 Thermor is over 20 years old. Propane.
Made in England. On demand instantaneous hot water heater. Direct vent out the wall. No electricity required. Does have a pilot. Starts heater by water pressure. Works perfectly. Unfortunately Reagan, Bush, Clinton did away with pilot light appliances. Recently took cover off and all still looks new inside. Works perfectly. |
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Two things I want to add to this discussion.
(1) Legionella: I did an experiment today. I turned the thermostat to about 140 degrees (it only has markings for 125 and 150). The water heater is in the basement, which is about 45 degrees. I had not used the heater for about two weeks. I ran the heater 1h 15 min. The temperature at the kitchen faucet was 130 degrees. I ran the heater another 15 minutes and the temperature at the faucet was 140. So total 1 hour 30 minutes to reach 140. Research shows that to kill Legionella it takes 140 degrees for 32 minutes. Granted, the temperature at the faucet is lower than in the tank. Still, this experiment shows that with a cold tank, it takes a fairly long time to heat the water to 140 for 32 minutes---perhaps 2 hours. (2) My new plan: I opened up the panels on the heater and found that it only has one thermostat, at the top. I'm thinking of disconnecting the lower element. I think the top element would provide enough hot water for a good shower. Two questions: (1) Do you see any problem with this plan? (2) Can I disconnect the lower element myself? How would I do that? What would I need to be careful about? (Response: Turn off the breaker. :rolleye1:) I have some R30 insulation that I plan to wrap around the tank and put on the top. I will also insulate the pipes. The I'll turn the water heater on for one month and see what my electric bill is. This will be in lieu of the best solution, which is to get either a smaller tank or an on-demand heater. |
Sailin, is this a hobby for you?
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Except the payback or break even will be about 22 years. Sounds like a real good idea. Pay the electric coop piper. Or pay the plumber installer piper. Or pay the propane company piper. One of those pipers is going to win out. |
I'd recommend you have an electrician, or someone with very solid electrical skills, do the disconnect of the 2nd element. You've stressed safety all along the way with your research and changes and re-wiring water heaters is definitely not safe for someone to just get some advice and try themselves.
And, just once again tossing in my 2 cents, I wouldn't do it. You have a water heater, let it heat water, shut it off when you don't want hot water. You are concerned about legionella, yet you are proposing heating SOME of the water in the tank to a temp you think the water is all at and for a period of time you think is safe. Yet half that tank or more won't be at that temp, won't be at the same duration, due to disconnecting one element. Makes no sense to me. |
I installed a solar array for a client about five years ago that had a fairly large all electric house, including the biggest electric tankless I have ever seen. I belive it was made by Bosch. The thing that caught my immediate attention was that it required two 30 amp and one 40 amp 240 volt breakers. The client explained however that he was very happy with the setup becuase most of the time it drew zero power, but if the kids and grandkids were all in residence for the holidays he never ran out of hot water. A unique situation to be sure but a good solution.
I've installed gas tankless heaters in two of my previous homes and for the most part were pleased with them. One however would act up occasionally because the well water occasionally had a small amount of very fine silt the would get by the inlet filter. After I figured it out it would onlky take a few minutes to remove the water metering valve from the front of the unit and rinse it off. In my current home I installed a Rheem Marathon tank water heater and I'm so pleased with it that I will probably install another in my next house. The tank is one "tupperware" plastic hull (like used in kayaks) moulded inside another and then they blow 3" of foam between the two hulls. Its efficient, has a lifetime warranty, and is very light and was easy to install. Perhaps the smallest version of the Marathon series or an electric tankless would meet your needs? The garage space were I placed my 70 gallon Marathon has 12' walls and I was able to weld up a rack that elevated the water heater by four feet and placed this next to my basement woodstove. Then I formed 60' of 3/4 soft copper pipe around the woodstove's flue pipe and tee'd the top hot outlet from the loop into the Marathon's outlet to the domestic water and radiaint floors, and tee'd the return from the water heater drain back to the feed to the coil on the flue. It works simply and perfectly using the convective rise all winter, and the natural striation of hot to cold water keeps the lower portion of the loop from pulling heat out of the water heater in the summer. My water heating costs in the summer are minimal, and in the winter are virtually nil. Two caveats to this system; one would want to install a mixing valve in the domestic feed because the water in the tank can get very hot, and second there should be absolutely no shutoff valves anywhere in the convection coil loop. As long the loop is open the water will flow constantly, but it there were a shutoff and the flow stopped it could result in a steam explosion. I did install a 180 degree boiler pop off valve in my loop and plumbed the drain down to a pail on the concrete floor just in case, but it only activated once during an extremely cold windy night and even then only relieved itself of a gallon of water. |
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Example: Health safety of using only the top element. You can only answer that by thinking about questions like: Does water in the lower, middle, and upper zones mix together? Or does hot water at the top remain at the top, while lukewarm water remains in the middle? If water in the top zone is heated to 140 degrees for 32 minutes, is a short shower drawn only from the top zone, where Legionella has been killed? Or is there a risk that lukewarm water from the middle zone will end up in the shower water? Is using only the top element any different from using the top and bottom elements with regard to bacteria? After all, even with two elements, there are still heat zones in the tank from cold to lukewarm to hot, so wouldn't that be equally dangerous? When you're taking a shower you can sense when the water is getting colder---is that dangerous? Somewhere in a two-element tank there has to be water in the 68°–122° (some sources say 130°) zone where Legionella grows. I surmise that if the thermostat is set to 140, the water in the middle zone never makes it to the faucets because hot water rises to the top of the tank. There is no way to ensure that the entire tank is 140 degrees all the time, and it's not necessary that that occur. So the question becomes, is there enough HOT water at the top of the tank for low usage, such that one element would be sufficient to provide Legionella-free water? And if a person uses more water, will one element replenish the hot water fast enough for safety? My intuition says that one element would be enough for my low use, but I will try to confirm that before turning off the bottom element. Some people have no patience with such questions and say, "Just turn the heater on 24/7 and get it over with." But inquisitive people have spent a lot of time investigating just such questions because health safety, fire safety, and conservation of water and power are important to them. Not being curious is what led to Legionnaire's disease outbreaks in apartment buildings and homes. People just blindly accepted statements that water heaters should be set at 110 degrees to conserve power, or that 125 degrees kills Legionella bacteria. Even the government issued such statements. Science proved them to be false. Now it's hard to go back and change people's minds about what they heard for years. Is your water heater set to less than 140 degrees? Why? Is that based on facts, beliefs, or habits? |
Sailin, well said and I understand what you are trying to accomplish from your various threads. I also appreciate the discussions, they are interesting and I learn from the input from everyone.
When I say my 2 cents is I'd leave the hot water heater on, please understand it's not coming from a "spend the money, spend the energy, stop trying to save" point of view. To the contrary, I'm very interested in saving energy, renewable energy, and saving water, not to mention am just generally environmentally conscious. Instead, my reasoning comes from a lot of experience not only as a homeowner, but also in various industrial settings where I've got a lot of experience with heating, cooling, various fuel sources, etc. My experience tells me that generally it's best to operate a piece of equipment the way it was meant to operate. Meaning, run your hot water heater set up the way it was made to operate, shut it off completely when you choose to. That's all. And I may very well be wrong about that, I'm just giving my opinion. |
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