Tankless water heaters- realistic as boosters?

Discussion in 'General Plumbing Help' started by jeffpas, Aug 14, 2014.

  1. Aug 14, 2014 #1

    jeffpas

    jeffpas

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    Hi folks,

    What I have is a building being renovated divided into a triplex, but the apartments are pretty small. One unit is just one room and then a little kitchen and shower, 2nd unit has a tiny kitchen, bathroom with shower and back bedroom, and upstairs unit has a full bath and kitchen (2 bedrooms).

    The building came already with a 40 gallon water heater in good shape which everyone is saying is not enough for a triplex. No idea if the previous occupants complained.

    The problem I have here is the largest stock water heater in the hardware stores is 50 gallon, and after that they start calling them 'commercial special order' with astronomical pricing accordingly. I see no use in paying all new and install from a 40 gallon to a 50 gallon its just not enough to make it worth the cost.

    Now about these tankless water heaters......

    Say I installed a few, maybe one for each shower/bath (3), then left the water heat on as normal.
    Would it be as simple as the tenants turning the dial and using less hot water, aka, the 40 gallon tank goes farther? Do you see what I am getting at.

    I don't see taking out the tank, and installing all instant water heaters, but it might be worthwhile to add a few. I'm just wondering if that setup with an active water heater would actually work.
    Thoughts........?? Experiences............????
    thanks
     
  2. Aug 15, 2014 #2

    phishfood

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    Any plumber can get 50 and 66 gallon water heaters all day long without dramatic cost increases from a 40.
     
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  3. Aug 15, 2014 #3

    Matt30

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    You could also buy another 40 gal and have a plumber twin them together. Added cost on electrical but whatever gets you off the tankless system
     
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  4. Aug 15, 2014 #4

    jeffpas

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    why 'get off the tankless system'? Is that a good thing?

    Kudos on merging in a second water heater, that had not occurrred to me or was suggested by anyone else I've talked to to date.
    But I would assume there is a cost economy of heating one say 80 gallon tank, as opposed to two 40s side-by-side? How much is the difference in the gas and electric bill I wonder, crippling? I would assume the water bill difference would be zilch.

    I can get tankless units for about $150 apiece, and these rate at 1 GPM. Which I hope/assume is enough to run a shower without gripes. So we're looking at about $500 going that route plus installation. Thats assuming a scheme could be devised to make them 'boosters'. The going idea would be to cap off the showers hot water lines entirely and have them drawing only cold, then fork and heat one side for the taps on each. That way the showers don't draw any hot water from the 40 gallon tank. Seems in theory would work. Though not sure about water pressure.

    On the other hand, I can get a 9 year 40 gallon water heater for around $387. The tankless units appear to only have a 1-2 year warranty, and may have other problems I don't know. Plus merging the one 2nd water heater I assume would cost a lot less install time than retrofitting 3 tankless units if such can be done.
    Objections?
     
    Last edited: Aug 15, 2014
  5. Aug 15, 2014 #5

    jeffpas

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    OK bump, I'm finding 66 gallon tanks and even 80 at reasonable prices but they appear to be all electric (which I wasn't looking for).
    Strange size, 66 gallon.... I would have never guessed.

    I wonder why they only have these sizes affordable in electric, unless I'm just not seeing it. The current tank is retrofitted for gas, and my assumption is all things equal gas water heaters are cheaper to run than electric. I don't know where these plumbers are getting reasonable gas 66's, because I don't see any being sold for under $500. But I'm finding tons of electric ones that are. Perhaps they have a secret wholesale warehouse somewhere?
     
    Last edited: Aug 15, 2014
  6. Aug 15, 2014 #6

    johnjh2o

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    Gas is a different story. 50 gallon is the largest you can get that are not considered commercial. You do realize that and residential water heater (gas or electric) that is used for commercial voids any warranty.
     
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  7. Aug 15, 2014 #7

    Matt30

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    Also i do believe if you are bumping up to anything from a 40 gallon with 12 gauge electrical wire, you may need 10 Gauge for a 60 gallon. Thats how ive always understood it.
     
  8. Aug 16, 2014 #8

    jeffpas

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    what do you mean 'used for commercial'? Oh no, don't tell me a rental house is considered commercial. For god sakes, this building has less square feet than my own, and I don't have a very big house lol.
    In sales terms, anything sold "commercial" usually means prices double for everything and a mob of vultures swoop in and rob you blind.

    The entire building has 3 bathrooms and two of them are as small as closets with a shower only.... I can think of many residential homes that have more.

    OK I found a 65 gallon natural gas water heater for $674.49 free delivery.
    9 year warranty. I think if hot water is so important, I may as well just go with this. As far as wire, I'm already hiring an electrician for other work we may as well spend some more dough and change that too.
     
    Last edited: Aug 16, 2014
  9. Aug 16, 2014 #9

    phishfood

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    1 GPM tankless electric will do a bathroom hand sink, but tend to be marginal even for that.
     
  10. Aug 18, 2014 #10

    jeffpas

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    I think the tankless solution is dead on arrival. The idea of conserving fuel by only using water heat on demand seems logical, but they're so freaking expensive its just not realistic.

    Also the warranty on even the 1GPM tankless starts to get weasely after 1 year, and goes downhill from there. If I can get a 9 yr warranty natural gas 65 gallon gas tank for around $670, crimeny one single tankless shower fixture costs half that alone if I have to step up to a size greater than 1GPM, and even that may not heat fast enough for a shower. Plus It seems like less hassle too to have one tank to worry about instead of 3-4 tankless units. Thats a lot less machinery to potentially break and the tankless have special maintenance needs.
    And of course buying one tankless big enough to run the whole operation here would be pricey enough to make the Koch Brothers cringe :/ Seems I've made a decision to go old school, feel free to shoot the messenger if you disagree.
     
    Last edited: Aug 18, 2014
  11. Aug 18, 2014 #11

    journeyman

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    i think your best bet is to do what matt30 stated by twining two 40 gal heaters together. Also keep in mind tankless heaters are not instant hot water they are endless. I think by many standards the property you have would be considered commercial. the other guys in this forum might be able to inform you. i know where i live a multi-dwelling is considered commercial. whoever you have put in your heater make sure they pull a permit and that it is done right. the other factor is do you have enough room for two heaters or one big one. you could do a 100 gal. light commercial heater. remember if you change from a 40 gal to a 75 or 100 gal you have to increase the vent size up past the roof. not sure where you live but you can get a 75 gallon residential heater from fergusons plumbing supply. any big supply shop will be able to get what you need.
     
  12. Aug 19, 2014 #12

    jeffpas

    jeffpas

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    I definitely like the idea of twinning two 40 gallons it would be a lot cheaper, I don't have to haul off the one working 40G and there is room- but wouldn't the monthly power and gas bill to heat two 40G's be much higher than heating one 65 gallon heater? Twice as much, potentially?

    As far as your question, no. In our state a rental building is considered commercial at 4 units. Anything under 4 is a residence. That includes a house divided into 3 efficiency units.
     
    Last edited: Aug 19, 2014
  13. Aug 19, 2014 #13

    jeffpas

    jeffpas

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    OK just to note after doing the math I'm back to one 65 gallon heater.
    The new 40 gallon tank I'm looking at is rated at $277 a year average cost.
    The 65 gallon tank is rated $320/yr.

    Provided 65 gallons is enough, and I think it is..... as the two downstairs apartments are tiny as closets and have no baths just showers, 3 bathrooms total in the whole building. And let's not forget that the previous owner was renting all 3 apartments out on just the 40 gallon tank. For 20 years, apparently. Why they never complained, I don't know.

    The 65 gallon tank would cost $207 more to buy at first...... but would save about $230 in heating costs every year over heating the two 40s.
    ( 2 x $277 ) - $320 = $230

    That's assuming the old 40 gallon rates at $277 operating costs per year also, and its probably less efficient at that.
     
    Last edited: Aug 19, 2014

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