Bleeding Money

All the expensive roosters I’ve been putting off for so long because of financial uncertainty seem to be coming home to roost all at once. I need several expensive home repairs, a root canal (to be performed Monday. Oh, the joys), and there’s a few things wrong on both our cars I’ve been putting off. To top off the whole bowl of ice cream, last night I hear water running in my office. Not unusual, because the laundry room with all the appliances is on the other side in the unfinished part of the basement, and the laundry drains into the utility sink. But then I realized I had been hearing it for half an hour. So I go look and there’s water gushing out of my hot water heater. No damage, because it goes right into the sump pit, but now I need a new water heater.

So the question is, do I replace the tank or go tankless? My utility space is really cramped. I have no room to work. I can’t work on my electrical panel. It’s obviously not code. A tankless unit would fix all that. The problem is they are like twice as expensive as the old tank heaters. To top it off, the amount of work to put in a tankless is a lot more, as I’d have to make a wall penetration out the side of my house.

Anyone out there have experience with tankless hot water heaters? What’s your opinion? I’ve never owned one and never installed one.

40 thoughts on “Bleeding Money”

  1. They may have improved since 2006 (I sure hope so), but a few years ago we installed a tankless at a friend’s house. Within a few weeks, he found the tankless heater created too much fluctuation in temp for a truly comfortable shower, so he tore it out and went back to a traditional system.

  2. Tankless work well and economically most of the time.
    You have to consider your usage, the temp. of the incoming water, how hot you want your water at the taps, how hard or soft the water is, are you using well or metered city water, cost of the energy (either electric or gas), water pressure and flow, both into and out of the heater. Those are some of the things you have to figure out before choosing.

    1. Pay attention to the hardness of your water. My middle brother installed a good tankless unit in the crafts barn I’m currently staying while I wait for my apartment complex to be rebuilt and it’s fed by a well that produces very nasty (near undrinkable to me) hard water. As a result it’s built up a good layer of minerals which come loose as small particles all the time, clogging up my shower head.

      But if you ignore that, and size everything right so that it will stay on continuously while you’re taking a shower, it’s very nice. As Polumetis says, “those long showers rock“.

      1. Yes to that. If you have hard water, don’t go tankless. My neighbor went through two in three years before going back to the tank style.

        1. Or treat the water. I would imagine you might get a duplex double column water softener or a simplex single column and time the regeneration of the single column carefully. At the house where I grew up a short distance away which also has hard although not nasty water we have a simplex softener and tank heaters.

          1. A simple vinegar solution run through the tankless system once a year will keep it running no matter how hard your water is. Make sure you install the fancy bypass valves that let you pump the vinegar out of a bucket through the unit and run it back to the bucket. Makes the cleaning chore super easy.

            The through the wall penetration can be fairly simple if you have the right size hole saw and an outside wall space to work with, it’s much less fun and much more expensive if you have to run the pipe a fair distance.

            Tankless units are only more efficient if you have stretches of time where you don’t use any hot water, ie the family is gone during the day. My house doesn’t offer that extra efficency because the wife is home most of the day and hence takes a shower mid-morning and does laundry and dishes throughout the day.

            Sizing is incredibly important. During the summer our incoming house water can reach 60F, during the winter it runs 35-38F. Thats a 90 degree temp rise during the winter but only 70 in the summer. How many GPM do you run? My shower head runs about 2gpm, but if I fill the bathtube that faucet is almost 5gpm.

            Hope all this info helps.

  3. Tankless is great if you’re using a lot of hot water. I looked at it. The savings just weren’t there for me when a new heater was just $600.

  4. I’ll add that with a regular water heater, it’s not even an option for me to get back to the electrical panel. If a breaker trips, I have to wait for Sebastian to come home and take care of it since I can’t reach that far back.

    The part of me that looks at the house through the lens of a likely buyer (a couple) would see this as a huge drawback. Not to mention, if there’s a single woman buyer, then she’s going to need to be at least 6 feet tall to reach back that far.

      1. It seems likely that a stool and a stick would work, but it’d still be awkward as heck.

        And that (the current installation) seems like it’d never pass inspection in a million years – so despite the costs it might be best to have it rewired if you ever intend to sell.

        If a tankless heater gets out of the way of the breaker box, that’s a huge win regardless of the other factors.

        (On the main question, I only have indirect experience with tankless systems, but they do seem to generally work.)

    1. Why not relocate the tank?
      Having the electric panel blocked like that is unacceptable IMO.

      Soldering copper pipe isn’t very hard, plastic is even easier! Just prime and glue! Also having water that close to electric doesn’t sound very safe either, what if it springs a leek on the top and sprays water on your electric panel? Not a good situation…..

      1. There is no place to relocate it to. That’s the only part of the basement that’s not finished, other than where the laundry is.

    2. Code requires 36inch clearance in front of breaker panels. If you don’t have it, chances are you’ll have to fix it before you can sell the property.

  5. For moderate to high volume users gas (propane, natural gas) tankless water heaters are great. Do not get an electric tankless – to meet the instant demand the current draw is horrendous. Figure on a major re-wire if you go electric tankless. When I looked at electric tankless the draw was 60-90 amps during operation depending on brand and model. You probably have only 200 amps in your distribution panel.

    If you don’t use much hot water, maybe stick with a tank. I ran the numbers on my house and I use so little water payback on a gas tankless is 12 years. I put one in anyway because I have natural gas, amp draw on a gas tankless is 1.2 amps so I can run it with a UPS during power outages (when electricity went out my electric tank heater was useless), and my utility offers a $400 rebate per appliance; put in a year-round appliance (water heater) and you get a rate discount on all the gas I use. YMMV, check with your utility. Plus, I recovered a fair amount of garage space by dumping the tank. My installation did require a PVC vent pipe through the roof, which added to the installation cost. Sounds like you can go through a side wall. And, if I don’t use hot water I don’t use any gas. Mine has a wall mounted remote inside that allows me to up the temp when I need it, lower it when I’m done. Turns out it’s cheaper to bump it to 140 for the dishwasher (Bosch) than have the dishwasher raise the water temp with its internal electric resistance heater.

    There is a lag between faucet on and hot water delivery. There is one tankless I’s aware of –
    that avoids that by maintaining a 1-2 gallon reservoir of hot water so there’s no lag. More spendy, though. I haven’t noticed more than 5-10 additional seconds waiting for hot water at the most distant bathroom.

    Check on manufacturer rebates, utility discounts. Get one big enough – check degree rise at gallon delivery rate to make sure it will meet your needs. A little bit too big is better than a little too small.

  6. I have a tankless gas heater. I love it. It’s no maintenance, saves gas, and the lag to get hot water is like 20-30 seconds, which is not much longer than it was when I had a tank heater.

  7. Neighbor has a tankless – wonder where she’s going to come get water when there’s an earthquake and things stop working? I like having 40-gal potable on tap.

    1. I’d propose that one possible solution would be to buy a 55-gallon drum for storing water. Because Utah is filled with Latter-day Saints, and Latter-day Saints are big into emergency preparedness, you can buy these in some of the local supermarkets. Whether your neighbor does this or not is a different matter entirely.

      I would also add that it would be a good idea to bolt your water heater to the studs of your house, so that it wouldn’t get knocked over in an earthquake; otherwise, I would imagine that not only would you lose all your water, but you’ll have gas leak problems as well.

      I rent, so I haven’t done either of these things. There’s a lot that I need to do to prepare, not just for an earthquake, but for Zombie apocalypse as well (which, given the way the Federal Government is going, doesn’t seem like an unreasonable prospect…)

      1. Another option (in general, not really relevant to Sebastian and Bitter’s case because of limited space) is a second water heater tank, not hooked up for heat, just as storage.

        A PO of my house was a Mormon and I have a second water heater tank sitting full of water in my utility space.

        (It also feeds one of the hose bibs on the outside of the house, so the water gets circulated out occasionally, but there’s so little flow that sediment isn’t an issue. A good compromise!)

        That has an additional advantage over keeping a drum around for water storage of it always being full, so if the water main fails? You’ve already got your 40+ gallons of water.

  8. I looked at going tankless in my house a couple of years ago. I think some of whether it makes sense will depend on the age of your house. My house is almost 100 years old. What we found was the amount of work to bring the house up to code for tankless would have been about $1500 (in just labor). We needed a new exhaust vent for tankless as the exhaust is much hotter than a tank. We would also need to run a new gas line as the volume of gas that is required is much higher than on a traditional one. So with all that work vs $150 of code updates for the new tank I went the tank route, we won’t keep this house long enough for the tankless to pay back for us. From what I have read it seems like how well they perform really comes down to if you have good water pressure, most of the complaints I have seen about them seem to be people with low water pressure.

  9. Let google do your walking. There are several outlet type places that sell tankless for about 40% off retail. Be sure and size it right.

  10. Check on the tax rebates of various types of tanks. I think our DC Overlords are giving back considerable cash if you go tankless.

    I am on a similar run – new furnace in December, new water heater last month – and mine had to have the air exhaust which costs twice as much. That planned July vacation has become more theoretical now.

  11. I did the great water heater replacement this year and after gobs of research and lusting after a tankless heater – I got a traditional electric tank heater anyways.
    My circumstance is a little different tho, we don’t have gas so electric was our only option and the cost/savings math just didn’t work out. Especially because we would have had to upgrade our panel, also space was not as much of a concern. I ended up getting a brand new heater and built a platform filled with insulation to keep it off the floor, than wrapped the whole thing with more insulation and did the pipes to help save energy.
    The tankless jobs are pretty neat, but I really don’t think you’ll see savings equal to the extra expense of the unit it’s self. My recommendation in the end?
    Base the decision on the space savings. If the extra space is worth the extra expense, go tankless.

  12. Go tankless – I did my own, and it was well worth it. Gas is the only way to go (with electric pilotless ignition)- prices have also come way down (~$600) for a reasonable size.

    Make sure the gas line is up to snuff and large enough (at least 3/4″). The flue vent must be double-walled and go outside. Mine went through a brick wall.

    Delay to hot is about 20 sec and those long showers rock…

  13. My two cents: A very good modern traditional water heater is probably the way to go. Install costs for tankless can go very high, you may need to reline your chimney (it may not be rated for the heat, and if it is not and your do not line, damage/fire can result), you may need a backer for the unit itself (they get quite hot), and if you are paying for installing the thing, the total cost is 3-5 times what the 40 gallon unit (I just had installed this Monday morning, with upgrades to the gas line and so on), costs. Even if you buy the best (We put in Bradford-White on the advice of the guy I use for central air and furnace work). The units run starting at double what a traditional one does (900 and up based on my research), chimney liner if you go stainless (which apparently you should) is at least 200 bucks for the actual liner, plus about 3-4 hundred for the top kit, but can run 2-3 grand to have installed. Total cost for my house was going to be about 3200. I’m willing to bet since I live in a row house in Filthy that my house is smaller, so your mileage will probably vary somewhat. I’m very pleased so far with the 40 gallon unit, not even counting the cost difference (about 25% of the cost with a 10 year warranty).

    That said, if you do not plan on moving any time soon, the Feds are giving a nice tax incentive and the energy savings over 10 years (versus a new top-of-line traditional one, not a Home Depot special), it should pay for itself.

    1. I can vent to an outside wall, so I don’t need a new chimney liner. My plan is just to cap the current chimney flue.

      1. If your gas lines are up to it and your wall is masonry and you only have the cost of the unit and incidentals, you may be well served with tankless. Ignoring any rebates or incentives that may or may not exist for you, the units themselves are pretty easy. Average flow needs for a 2 person house are under 20 gpm (homework done when putting in a whole house water filter). So if your percentage need of that is 20-25%, 4-5 gpm hot (maximum), a good tankless will be 800-1000 dollars (as of last week anyway), versus 400-600 for a good tanked system of 40-50 gallons. Add in the cost of the kit for venting (no idea I would have had to use a liner), and you come up with a not unreasonable cost comparison, and a 70% or so space savings.

        If you do choose tankless, avoid the urge to go with a ton of gpm, as we found out with my in-laws, the amount the water is heated above the temp out of the ground goes down significantly with flow rate, and they do not seem to advertise this fact much.

        That is basically everything I’ve learned on the subject. I’ll let Mr. Dickens RIP now.

  14. I installed a Rennai gas tankless water heater five years ago. At the time my gas bill was $48 a month. Now it’s $9 a month. Temperature regulation is within a half degree, with steady output at 139 degrees.

    An electric draws nearly 100 amps, so if you do not have natural gas you will have to look your hand over there.


  15. Has anyone else heard that the tankless do not last as long as tanks? So the ROI is much harder reach than expected?

  16. I’ve got experience with both. Tankless gas are the way to go especially for those with second homes or portions of larger homes that go unused for long periods of time. They are great for new homes or during major retrofits.

    That said, the math does not work out for most “replacement” applications – in other words, just replacing a water heater. The new heater tanks are really quite efficient (I have had them hold water warm enough for a shower for more than 5 days in summer). The extra cost you put into the tankless has to be spun out against the amount of fuel (elect/gas) you would have bought with the same money and a traditional system. Also, the installation is usually non-trivial (extra cost).

    I’ve done the math for four applications of my own (houses/apartments). The short answer for me is if I am building it new or if it calls for an architect, then I go tankless. Anything else and I go traditional, especially for repairs. You can replace a tank yourself but a plumber can do it in no time and require no permits.

    That’s an issue you might want to consider: replacing a traditional tank usually does not call for a permit. A tankless system will. That means an inspection, and almost surely a red tag on the electric you say is not up to code. Now add the cost and time of getting an electrician to get you up to code – all while living with no hot water.

    I am finishing off 1800 foot of unused space and did the math – it wasn’t worth it. But the vacation rental place getting a complete tear-out makes more sense because I am already into big bucks for the plumbing anyway (and the roof, walls, etc.), plus the fact it goes long periods with no use. In simple terms, I can spread that investment over a greater period of time and recoup the cost over many years (10+). Repairs are ‘maintenance’ and generally I need a 5 year (or less) ROI on them. But everyone has different math that works for them…

    Good luck.

  17. I suspect a couple of posters have their math backwards. The tank water heater keeps, typically, 40 gallons of water hot 24/7. The energy needed to keep that much water hot is not trivial. So your energy provider wants you to turn your “hot water” back to “luke” to save money. I hate luke warm showers – and the scum left on clothes washed in “luke” water.

    On the other hand, the water in a tankless heater is at ambient. NO energy is expended keeping water hot. You only warm the water you use when you use it. The Rennai puts out “140 degree” water, dropping to 138 at 10F, and uses one fourth or less of the energy the Rheem used. And if I want to I can adjust the hot water temperature on the fly from inside the bathroom. And, it takes up far less room than any conventional “Vesuvius” type water heater. 18″ W, 24″ H, 8″D for mine as I recall.

    The things to watch for on tankless is gpm at full rated temperature rise and current draw. They range from 1.8 GPM to 8 GPM. 1.8 GPM is pretty good for hand washing dishes but it is inadequate for bathing and laundry. Unless you find cool showers or hot dribbles soothing.

    An 8 GPM electric will probably draw 120 Amps which means a 200 amp breaker, and likely a separate box for that breaker. If you have a standard 200 amp service and electric heat, that is not good.

    Gas takes close to 250,000 btu/hr supply capability, but it is only on for a relatively short time each day. And you do not get hit with a surcharge for peak use.


  18. I went Rennai a few years back. A few challenges had to be overcome. 1 1/4 gas line had to be plumbed over, and the exhaust forced a relocation of the kitchen vent. Those, however, are just my challenges and relate a lot to just how my house was laid out. I certainly have no regret.

    Mine was a pro install, but having watched one now, it could be DIY.

  19. I have a tankless and like it for two reasons: I can take a crazy long hot shower when I want to, and when I am not home (I travel away from home too much), it burns no energy.

    There are some practical aspects of them which you need to be aware of. I have adjusted to them, and I expect everyone does, but they can be a rude surprise at first.

    Think about how they work — they have burners which heat the water as it flows past. That flow takes a while to reach you.

    If you set the flow at half speed, it takes twice as long. The flow detector in the heater takes a few seconds to react and adjust the burners sometimes, or for more burners to come online.

    There is a minimum flow, below which it shuts off because it can’t put out so little energy and would scald you.

    There is a maximum flow, above which you get less warm water.

    As the hot water flows thru the pipes, the boundary between cold and hot fuzzes out, so there is no sudden change in temperature, but a change which takes several seconds and gives you plenty of warning to get out of the way, so you can avoid getting scalded or frozen as long as you are alert.

    Tankless heaters are rated by how much they can raise the water temperature at maximum flow, so the actual temperature changes with the incoming water temperature; I have a 1000 gallon above ground storage tank, and the difference between summer and winter is noticeable. It might not be so noticeable with underground water delivery.

    In a tank heater, the hot water exit pipe also contains at least warm water, so when you turn on a faucet, you get something more than cold, and furthermore, once the main hot water reaches you, it is always the same temperature, whether you change the flow or not. Not so in a tankless, where you have to wait a couple of seconds for the heater to detect flow and turn on, then wait for that new hot water to reach you. In my converted house, it’s about 45 seconds. A repiping could shorten that considerably, but take it into account.

    Suppose you turn the hot water on full to get the new hot water to you as soon as possible, then turn it down once it arrives. Slow it down below the minimum flow, and you will suddenly get cold water in the not water line, but it takes takes several minutes to arrive because the low flow takes longer to move the same amount of water. Then when you correct by raising the flow, it takes a while for the new hot water to arrive.

    I have also found that in the shower especially, changing the flow affects the temperature. I do not fully comprehend why it happens, but I think it is related to the heater flow detector taking a few seconds to react to changes, so when you change the shower hot water just a bit, the next few seconds of water thru the heater get the same energy as the old flow, ie, the water is a different temperature, and when that hits the shower, it has spread out enough in the pipes that you may get 10-15 seconds of cooler or hotter water … your instinct is to adjust the shower temperature, which changes the flow again, and you are always battling the delay time between heater and shower.

    I have also found that big quick changes apparently shock the heater more than small gradual changes. Turn on the shower full, get the hot water, turn it down quickly, say to 1/3 full, and now the flow time from heater to shower is 3 times as long, so a minute or two later, the water temp changes for no apparent recent reason …

    In all these cases, I adjusted within a couple of weeks and don’t have nearly the problems I first did. When the temp changes like that, I just wait it out, it is never a huge change, scalding or freezing, and 10-15 seconds later it corrects back to what it was.

  20. Just another option to consider. Can you do a solar hot water heater. My understanding is that many units even in winter produce water so hot it has to be diluted with cold water. Not sure if that would allow you to have a smaller tank.

  21. Since first cost is a big issue, I would suggest sticking with a tank HW heater. Perhaps you could look into a horizontal ceiling mount type heater (assuming you have the overhead space-see below)? This would require repiping the HW, intake/exhaust, and gas pipes, but it may solve your code issue with the panelboard.

    IIRC most codes require 3′ horizontal clearance in front of the panelboard and an additional vertical clearance above the panel board (I don’t remember the numbers exactly), so you probably won’t be able to mount the tank immediately above your panel. Even if codes don’t prevent it, think about what will happen if it leaks onto all of your breakers… yeesh!

    If you decide to go tankless, I would checkout the condensing type. These are very high efficiency (high 90% usually), which means the resulting flue gasses are much cooler, and you typically can use PVC piping with these (I assume that’s what your tank uses). The downside would be condensing type typically use stainless steel heat exchangers so the equipment would cost more. You’ll have to see if the labor savings with reusing the PVC flue pipe will make it worthwhile.

  22. On the newsgroup, tankless heaters are almost universally shunned, mainly because of the expense and difficulty installing them. They almost always require a separate circuit (for each faucet) or gas plumbing to the needed location.

    In your case, a smaller capacity water heater – say 20 gallon – may be a solution.

    1. They almost always require a separate circuit (for each faucet)….

      Hmmm, that doesn’t match what I’ve observed in the crafts barn I’m living in right now but with only two of in it I might be missing some failure mode. What’s supposed to be the problem?

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