My 50 gal electric water heater has failed after 60 years of faithful service.
I’ve been intrigued by the idea of using a whole-house, tankless, on-demand, electric water heater. It would be nice to reclaim some space in the basement utility area and save on running costs.
My house is 1.5 baths, and includes a dishwasher and laundry facility. There is no natural gas or propane available, so I’m limited to electric. Service inlet is 150 amps, 240v, and handles an electric range, but not an air conditioning unit. Other than four or so computers, there’s not much heavy draw on the circuits.
Water is supplied by a 330ft deep well; filtered, but not softened. Tests run last year show a pretty clean source, but high in iron, and the filtration does little for that.
One plumber says he has never installed an electric tankless system, and I would need a 400 amp service to handle it. That I doubt.
A building inspector friend has suggested that if the system has some kind of auto or manual back-flush, it will work fine. Clogging the fine orifices is a problem in my area.
Another plumber says the iron will make an on-demand system useless in a short while, and I’m wasting my money.
I think I will need a building permit for a tankless system, but not for a replacement, standard tank-type system. Add $100.
Any thoughts? Cold showers are not attractive right now.
My daughter has one at work and she said they often have to heat water on the stove because they can’t get enough hot water. She doesn’t work at the Y or a laundry, or anywhere that uses a lot of water.
A friend of mine, who is an engineer, was going to get one but after talking to people said he’d heard more stories about problems than about benefits, so he decided against it. He has lived in Europe and travels to Europe and Asia extensively, so he went into the idea if getting one with a positive outlook.
Those are just anecdotal, and I’m sure you can find lots of people who have positive experiences. I don’t think the models here and the ones overseas can be that different, so I don’t know if my daughter and my friend just looked at duds, or what.
I just cannot imagine an electric AND tankless water heater.
The tankless design is predicated on the instant availability of a very large heat source.
Electrics are noted for “slow-but-sure”.
Look at max throughput while raising temperature 40 F.
Now go look at gas tankless and see what they can do for a place with your (water) loads.
Ignore everything except the rating for your load.
Found a gas unit that would work? NOW look at its throughput. If you can’t find an electric which can match it and consume no more power than you can provide, something has to give.
If you really want tankless, what would it take to put propane on the property?
IOW: that 400 amp estimate just might have been reality.
Why not? Can you imagine an electric stove? Oven? Feast your imagination on one like this.
So you can’t imagine that an electric element, if big enough, can provide sufficient flow?
Here’s a chart.This chart (scroll down) says that Steibel’s model 29 can handle a 60 degree rise at 3GPM. Continuously, unlike a conventional tank unit. Hot enough for you?
About $5000. I’d need a tank and lines brought into the house. Also new venting because gas isn’t clean burning like electric. Not cost effective.
Ever seen small, under-the counter water heaters? They are installing those in many new houses. Hot water instantly – you don’t have to wait for it to come from a tank far away.
One of the advantages of tankless is it costs nothing to run if you aren’t using it. That seems like an efficient use of resources to me. Tank units, no matter how well insulated, must maintain hot water all the time.
We did a whole-house remodel last year and looked at the water heater options during that process.
What we found is that almost every source, including energy.gov, said that the on-demand styles took a very long time to pay for themselves and needed more maintenance.
I would get another estimate to see if it matches with your plumber’s assessment, decide how important the space you’re saving is to you, and investigate using multiple point-of use tankless heaters because that might not require an upgrade to your electrical service.
The one you linked to says it needs a 50amp circuit. Can you install that in your current 150amp service, or will you need to upgrade?
My mother’s house has only a 100amp service. It’s fine most of the time, but if I try to run the dryer while she’s cooking and some lights are on, I can trip the circuit breaker for the whole house.
I recently spoke to a friend of mine who is in charge of a plumbing supply company. He told me that for a single person that doesn’t stay home and use water all day that it would be a good investment because you wouldn’t be paying to have a tank of hot water ready at all times. The advantage goes down if you have people using the thing all day.
I like the idea for the aspect that I can mount it outside the house and make room in laundry room for full sized appliances; but I worry about the resale value of the house when a couple with teenagers really start getting serious about making an offer.
I was looking into this the other day, as we’re building a new house right now. We’re living in a shop on the property while we build, and it has a gas tankless. The gas tankless works great in the summer, not as well in the winter when the incoming water is near freezing. We still get hot water, but not quite hot enough.
These seem to get pretty decent reviews, and they’re not too expensive. You do need a LOT of open space in your electric panel–6 spaces, I believe. Do you have that? 150 amp service might be a problem.
The other thing I noticed was the predicted incoming water temp for my area was a good 20 degrees higher than what we actually experience. So you might want to check on that before you assume you have enough heating capacity.
Ultimately, we decided to go with traditional tanked heater, but we don’t have space issues.
I think tankless water heaters are great, but electric models require a truly recockulous amount of current. That’s because it needs enough juice to heat up a lot of water instantaneously on-demand. A traditional tanked heater only needs enough current to heat up the tank relatively slowly and keep it hot. One tankless model I looked at required 100 amps all to itself, and that was just big enough for the two bathrooms at my friend’s house. Your electrical service might not be able to handle that.
Even gas-fired tankless heaters sometimes require service upgrades to get enough gas into the thing all at once. I think those are a superb idea if you already have gas service or propane, but obviously that’s not an option in your case.
I purchased and installed this gas water heater several years ago, and I have been completely happy with it. Things may have changed by now, but when I was researching the various types of tankless heaters, I found that the electrics just couldn’t keep up to whole-house use and did a poor job.
Mine is configured for propane, and I have a 1,000 gal tank buried in the yard. They can also be configured for natural gas.
The only maintenance that I have performed so far is a yearly flush with 5 gals of vinegar, which is probably overkill since my well water is not at all hard.
I didn’t buy this to gain more efficiency…I bought it because I wanted an alternate fuel source, and I wanted to easily have hot water during a power outage - this tankless runs with very little power, and the only heavy lift for my generator is the well pump.
That model is about half the price of the ones I was looking at, and thanks for the link. Maybe a German-made model isn’t worth twice the price.
I could be wrong about my service inlet, and I’m trying to reach my electrician to find out. It might be 200 amps – it doesn’t say anywhere on the box. I have 9 open standard-sized breaker slots, and 2 could be reused if the tank heater connection was recycled.
My incoming water to the heater will vary from 42F to 65F. The well water comes in to the house at 42F year-round, but sits in a pressure tank in the basement and in the summer, could warm up to 65 max.
I’m getting cost estimates all over the map. One plumber who I have dealt with before said a replacement 50gal tank heater would be $1K, including removal of the old unit. If I could get a tankless installation, including the necessary wiring, for under $1.5K, I think I’d give it a shot.
My first thought: 60 years?!? Holy Cow! Ours didn’t last more than about 10! Actually, what happened was that I purchased a timer for ours and after a couple of years the tank crapped out on us. That is, the fellow who replaced our tank with a tankless system thinks that the constant re-heating of the water (ours was a gas heater) messed with the metal coils inside the tank and made it difficult for the timer to regulate the temperature of the water (which made my wife QUITE angry). So, since my wife was getting tired of the water not being warm enough for her, we ditched the tank and got a tankless system (this was about a year ago). In general we like it but after initially working just right we had the guy who installed it come back to check on something (I think the pipes were leaking a bit) and now with some of the faucets (in particular the kitchen one, in our case) it seems to take forEVer for hot water to come to it (or, at least, certainly longer than it’s supposed to). Next time we have the guy come by (I think you have to have the pipes cleaned at least once a year because of the buildup associated with tankless water heater systems), which should be pretty soon, we’ll have him look into that. Other than that, though, we like it. At least, I haven’t heard my wife complain about it which is all that matters, right?
I’ve had electric tankless for the past 7 years. We have a 200 amp service, but that was all upgraded during a big reno which also involved installing geothermal heating; basically my entire house runs on electric… so I don’t know if you’d need quite the same service I do.
Maintenance isn’t the problem some of your contacts have suggested; for example there’s no way dissolved iron in the water would render a heater useless; they just don’t work that way. My heater has a simple screen on the inlet; you can undo a threaded fitting and clean it as often as you want. I looked at mine after 5 years continuous use, and it didn’t have a spec of debris to remove. We are on well water too, soft but high in sodium (it’ll kill the lawn). Remember you’ll be running water essentially straight from your source through the heater; there’s really no time for anything to precipitate out and clog the filter that wouldn’t be clogging the rest of your plumbing too. I’d say a tankless system would have less chance of deposit-related maintenance required because there is very little heated water left sitting in it between uses, and water that is in it flushes entirely out. A tank system will have a large amount of heated water continually precipitating dissolved minerals out 24/7 and settling on the bottom; they don’t flush entirely out when water is drained or added.
They are extremely simple to install; you just need the electric and plumbing attachments ready (that may take professional help, but it’s basic stuff). When I replaced and re-installed mine, I did the whole job myself with a screw driver, pipe wrench, and some teflon tape.
Electric tankless will take some getting used to if you’re used to an old-fashion tank heater. The biggest difference I noticed was that our old tank system allowed you to turn on every faucet in the house and blast hot water for 5-20 minutes… and then you’d have to wait a few hours. Short bursts of hot water are easy with a tank system (rinse your toothbrush, quick hot soapy scrub of dirty hands, rinse the extra tomato sauce out of a pot for 10 seconds…), but you can’t do that with electric on-demand.
It’s true that electric tankless heaters take longer to reach operating temperature; on average mine takes about 30 seconds (vs 5 seconds for tank system). When you turn on the stove element it takes a bit to get glowing red. I imagine a gas tankless system would reach max temp quicker, but I don’t have experience with those. Tankless will also have a max flow rate they can produce water that hot at. Remember your water must increase in temperature by 50 degrees over maybe 1/2 a second while its flowing through the heating elements; that’s a pretty significant feat and why you need the big electric service to supply that kind of power. To deal with that you can either buy a bigger heater (with a greater heating capacity and requiring a bigger electric service), or learn how to space out heavy water usage… like don’t run the dishwasher and bath tub at the same time. Also, big faucets can usually let through more flow than a small to medium heater can handle… we can’t run our bathtub full blast (the gushing water can only get luke warm), but all the smaller lines we can. A low flow shower head and filling your tub slower would probably be sufficient.
Watch the model you go for and don’t try to find some cheapo version from a thrid world country. In a recent thread on this same topic, it was brought up that there are tiney cheap tankless electric heaters used in poorer countries designed to supply hot water to a sink in hotels/hostels. They work, but don’t try to run your house with one. Steibel is the type I have, and I think the company has been around long enough to know what they’re doing. Tankless systems are also by no means new… my dad told me they were common in urban Germany around WW2 when he was a kid. I think $300-$500 is a reasonable price for a quality heater, and maybe 1/2 to 2/3 that for a conventional tank heater. So the main cost you’d be looking at is getting the services ready to go; $1,500 should be more than enough. I’d suggest looking for the recent thread on tankless from < 1 year ago; it had more costs estimates.
