How to choose a gas hot water heater? (Slightly different)

Discussion in 'Water Heater Forum, Tanks' started by coconutpete, Sep 7, 2012.

  1. coconutpete

    coconutpete New Member

    Messages:
    14
    Location:
    North CT / Denmark
    My water heater is manufactured in 1969. It still makes hot water very well, but there's rust around the overflow valve and god knows the last time this thing saw maintenance. I'll admit I haven't touched it since I moved in 3 years ago.

    I want to replace it with another 40 gallon natural gas water heater.

    My problem is ... how do I pick one? There are TONS of reading material out there but it's all about picking a style of water heater. Natural gas vs. electric. Tank vs. tankless etc. I already know what I want, I just don't know how to pick one.

    Water heaters seem to have become a "disposable" item like so many other things - I can pretty much forget about getting 40 years out of another one. You pretty much replace them every 5-10 years so ...... is it just go to Lowe's and pick one or do you spend extra coin on a "fancier" one? Do I buy the $400 Lowe's one, or the $800 one ?



    Side question: My Furnace guy keeps telling me my current one is probably made of copper and probably worth some money - how do I determine what it's worth doing with this thing?
    Last edited by a moderator: Sep 11, 2012
  2. coconutpete

    coconutpete New Member

    Messages:
    14
    Location:
    North CT / Denmark
    OK, so more reading .......

    The only thing I can find that EVERYBODY seem to be 10% unanimous on is don't guy a Whirlpool water heater haha.
  3. Dana

    Dana In the trades

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    Location:
    01609
    In almost all instances natural gas will be cheaper to operate, but if you don't have the gas lines/flues already in place the installation cost would be substantially more than swapping in an electric for another electric. (At CT utility rates heating water with electricity is more than 3x as expensive.)
  4. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,308
    Location:
    Yakima WA
    No question about gas being more economical than electricity for heating water. It also is much faster. I would suggest either a GE/Rheem or Bradford White. Yes, there will be some expense for installation. You might want to consider a power vent as these do not use a vent out of the roof. They vent with PVC through the side of the house. Tankless require a much larger gas service than is normally in a residence, so this would add a great deal to the installation.
  5. coconutpete

    coconutpete New Member

    Messages:
    14
    Location:
    North CT / Denmark
    Tankless isn't even an option. Too many variables in the next few years.

    Electric i DEFINITELY not an option. I have a gas water heater there now, going to electric would be backwards evoluion as far as I'm concerned.

    What I'm torn on is ... since water heaters have "de-evolved" from the one that's in my basement now which has lasted 43 years to something that lasts 10 years - does it even matter if you spend $800 on the Bradford White one or half that on the one at the big box store?
  6. MACPLUMB 777

    MACPLUMB 777 TROJAN WORLDWIDE SALES RP

    Messages:
    679
    Location:
    Houston, Texas, United States
    What people are missing is the simple direct answer
    since 2003 all gas water heaters are made to resets gas explosions
    These new systems is all still being worked on,
    right now the best of these seems to be bradford white, with rheem/ruud running a close second,
    lowes is noted as being the top seller of whirlpool !

    I hope this answers your question
    Last edited: Sep 12, 2012
  7. coconutpete

    coconutpete New Member

    Messages:
    14
    Location:
    North CT / Denmark
    Can you explain what this means?
  8. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,285
    Location:
    Cave Creek, Arizona
    It means that there have been some "rocket scientists" who used, or stored, gasoline around their water heater and demolished the house and themselves in the process. The new heaters have an FVIR system which immediately shuts the heater off before the explosion could occur. The original Whirlpool, American, and a few other heaters had a "one time" unit that could not be reset if this occurred and required replacing the water heater. Now they all are resettable, so that is no longer a factor in your decision. EVERY make and model water heater has failures so no matter which one you buy you could get 2 years of service or 25 from it, and it is all the luck of the draw. Do not spend too much time agonizing over the decision. The $800 water heater is usually just the $400 one with an extended warranty.
  9. coconutpete

    coconutpete New Member

    Messages:
    14
    Location:
    North CT / Denmark
    That makes sense - thanks.
  10. piezomot

    piezomot New Member

    Messages:
    44
    Location:
    Ontario
    Three days ago rubber pipe was disconnected inside of my dishwasher, and I reconnected it. Today it happened again, and I noticed my gas water heater started to release water over pressure release valve...

    I am thinking about on-demand tankless water heater:

    http://www.rona.ca/en/gas-water-heater-41355003--1

    [video=youtube;S88PBHDT0VM]http://www.youtube.com/watch?v=S88PBHDT0VM[/video]
    [video=youtube;Byhdt61IzGY]http://www.youtube.com/watch?feature=endscreen&v=Byhdt61IzGY&NR=1[/video]

    Any thoughts?
    Last edited: Mar 26, 2013
  11. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    A WH from 1969 is NOT copper. The only copper ones I have seen are very early 50's or pre-WWII
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,820
    Location:
    New England
    To go tankless, often involves upgrading the gas service line(s) and possibly the meter, and maybe even all the way to the street. It can be quite expensive, and depending on where you live, may not work well unless you lower your expectations or get a large unit or maybe need multiple ones...it's all about flow rates and temperature rise. Run your hand through a candle, and it may not get warm. RUn it through a blowtorch and it might. Depending on how fast (volume) of water you ask for at any one time, it can take a VERY big flame to heat it sufficiently to be useful. Course, if your max volume is low, smaller may work, or if your incoming water never gets below 50-degrees or so in the winter, it may be fine, too. A tankless generally will use more, sometimes lots more, gas than a furnace or boiler. This is the reason it needs a significant gas service. While an electric WH will have lower standby losses, depending on where the thing is and how good it is, it isn't a huge amount of money. They tend to have much better insulation than those from 10-20 years ago, and you can get a much more efficient burner design, which may not pay for itself over time depending on use and the future price of NG. With the minimum flow turn-on and wintertime issues, I prefer a typical tank WH - you can fill a tub at max flow without issues as well as get warm water at the vanity. Things that may not work out with a tankless unless you modify your expectations and procedures. A tank-type WH can survive without maintenance, a tankless will degrade, sometimes significantly, without annual service to remove mineral buildup.
  13. Dana

    Dana In the trades

    Messages:
    2,785
    Location:
    01609
    On-demand tankless heaters make some sense if you have some monster-tub to fill (like the 140 gallon spa in the master-bath), but have little rationale for most other applications.

    A showering (rather than tub-bathing) family would get better efficiency out of a standard gas heater (or a condensing tank) + drainwater heat recovery heat exchanger. A tub-bathing family with a standard sized tub would get better efficiency out of a 50 gallon condensing tank heater, with none of the tankless HW heater "personality problems" and with fewer maintenance issues.

    In tiny houses/apartments where space is at a premium there is sometimes a ratinale for hanging a tankless over the clothes washer or something to gain back 5 square feet of floor space, but that's an expensive 5 square feet.
  14. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,285
    Location:
    Cave Creek, Arizona
    quote: three days ago rubber pipe was disconnected inside of my dishwasher, and I reconnected it. Today it happened again, and I noticed my gas water heater started to release water over pressure release valve.

    1. You should have reconnected it properly
    2. The T&P discharge has NOTHING to do with the pipe in the dishwasher disconnecting., but an excess of pressure could cause BOTH things to happen
    3. Do you also trade in your car when the ashtray gets full, because changing to a tankless heater is about the same thing, if you don't want to cure the problem but just want to get rid of the symptoms.
  15. Dana

    Dana In the trades

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    I personally DO trade in the car when the ashtray gets full, since it's an indication some unhealthy bum has been camping out in it! :)

    But I'm glad somebody actually addressed the pressure problem, even though it wasn't what was being asked- thanks hj!
  16. WorthFlorida

    WorthFlorida Member

    Messages:
    105
    Location:
    Lake Worth, Florida
    Having sold water heaters for many years at a major retailer, here are some facts that most people gets wrong.

    1) It is not a "hot water heater", it is a water heater (it makes hot water).

    2) Gas is not more economical to operate. An electric water heater is nearly 100% efficient while the heating element is on. There is no loss of heat up a chimney as with a gas unit. In idle mode both water heaters are nearly identical for loss of heat through the insulation. However, the cost per BTU to heat the water is usually more for electric than natural gas. Hence, it may cost more to heat water with electric than gas but it depends on where you live.

    3) A residential water heater with dual elements does not use both heating elements at the same time. The upper thermostat is designed for when the upper part of the tank is cold, it will turn on the upper heater element to heat water so as it is draw off the top, it will be at least warm water at the faucet. When the water reaches the set temperature of the thermostat it switches the power to the lower element. The lower element will turn off buy the lower thermostat when it reaches temperature.

    4) All electric heaters are the same. No! depending on the model or size, check the wattage rating of the heater elements. Most are in the 3800 watt range but some can be 5500 watt. Never replace a 3800 watt unit with a 5500 watt unit unless your electrical connection can handle the load. For the average house the water heater is wired with 10 gauge wire on a thirty amp circuit. Older homes have 12 gauge on a 20 amp circuit.

    5) A gas unit can heat the water faster than electric (called heat recovery rate). Not necessarily. It all depends on the model itself; electric wattage ratings or the size of the gas burner. Each water heater will have this rating and it is not how fast the water will reach temperature of the tank, but how fast it can rise a given amount of water. It takes the same energy to raise 40 degree cold water ten degrees as it does to raise 75 degree cold water ten degrees. So if you have an electric 30, 40 or 50 gallon tank with a 3800 watt element, each will raise the water temperature at the same rate, the difference is when will the entire tank would be hot enough to use say for a shower.
  17. Dana

    Dana In the trades

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    Location:
    01609
    On #2 I'm not quite sure how you're divorcing "economical" from "cost per BTU". Economics is about $/BTU x efficiency, not just efficiency.

    On #3, hell YES it will operate on both elements, at least some of the time, even if they're controlled separately. (Perhaps you meant that to read "A residential water heater with dual elements does not always use both heating elements at the same time?)

    On #5, do the math. Only a few electric tanks will put out a max of over 4500W, which is 15,354 BTU/hr, at an efficiency of ~100%, delivering 15, 354 to the water. The 5500W electric heaters deliver 18,766 BTU/hr.

    Atmospheric fired tanks have a steady-state efficiency of ~80%, and very few have burners with input BTUs smaller than 30,000 BTU/hr, which delivers (0.8 x 30,000=) 24,000BTU/hr to the water. That is a heat rate over 25% higher than a 5.5KW electric, and 60% higher than a 4.5KW electric.

    Most 40 & 50 gallon gas-fired tanks these days have burners north of 35KBTU/hr, and recover in typically half the time of comparably sized electric tanks.

    I don't know of ANY electric tanks that will recover as fast as the smallest-burner gas fired tanks, but maybe bein' in the biz and all you can point to some specific models where that would be the case?
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