Quick basic advice on a dripping gas 40-gal hot-water heater

It turns out Rick is right.

The size of the home water heater (e.g., 40 gallons, 50 gallons, etc.) is nearly meaningless, as is the warranty period.

The only way the tank size plays any role in the selection process for purely physical reasons. Why? Because both the EF and the FHR already take into account the size of the holding tank so there is no need to even bother to look at tank size (other than for purely physical reasons).

Likewise, the warranty is always less than the average lifetime of a home water heater, which, at 13 years, is vastly greater than the 1-year labor warrantees all the heaters I looked at (from Sears, Lowes, and Home Depot) provided. (Note: The 12yr/9yr/6yr/etc. warranty figures often quoted by Sears/Lowes/HomeDepot are for PARTS! Not labor).

Thanks everyone for enlightening me ... If I didn't know better, I'd buy by the size of the tank and the warranty but now I know they are meaningless figures. The manufacturer WANTS you to look there but in reality, the truthy lies in the FHV, EF, and cost/therm.

I didn't realize you guys knew so much about home water heaters ... but I'm glad you do. In only two days, I was able to take my knowledge level, with your help, from absolutely nothing to being able make basic lifetime cost comparisons given any two home heaters.

Thanks!

Donna

Reply to
Donna Ohl, Grady Volunteer Coo
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Hi James, You're right.

I guess what I meant was I can "solve for X" without looking at the sticker. I can call Sears, Home Depot, or Lowes and just ask for FHR & ER and, from that (and my known cost/therm), I can compare two heaters side by side:

CHOICE A: Sears 33154 (marketed as Kenmore but made by AO Smith) FHR=97 EF=0.63 (41,045 btu/0.63)($1.21106/therm * 1 therm/100,000 btu) x 365 = $288/year

CHOICE B: Home Depot 183-717 (marketed as GE but made by Rheem) FHR=80 EF=0.58 (41,045 btu/0.58)($1.21106/therm * 1 therm/100,000 btu) x 365 = $313/year

But, you are right. If I were in the store, I could basically double the annual operating costs shown and I'd be in the ballpark.

Thanks! We learned a lot in this thread, didn't we!

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

Actually, the cost savings for a more efficient model is as follows: CHOICE A: Sears 33154 (marketed as Kenmore but made by AO Smith) FHR=97 EF=0.63 (41,045 btu/0.63)($1.21106/therm * 1 therm/100,000 btu) x 365 = $288/year

CHOICE B: Home Depot 183-717 (marketed as GE but made by Rheem) FHR=80 EF=0.58 (41,045 btu/0.58)($1.21106/therm * 1 therm/100,000 btu) x 365 = $313/year

a. Additional cost of more efficient model = $882 - $747 = $135 b. Annual savings of more efficient model = $313 - $288 = $25 per year c. Payback period = $135 / $25 * 365 / 30 = 65 months (5.4 years)

The overall savings over the average lifetime of a home water heater is: (13 years - 5.4 years) * $25/year = $190

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

Actually, since my cost per therm is far from the average used for those stickers, the sticker numbers are innacurate in my situation.

The sticker numbers might work to roughly compare two models in performance but they don't work to calculate the true payback period for two models.

For that, the math I've posted today should be sufficient (assuming the calculations hold water under scrutiny of this esteemed group).

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

Jeez.

I'd feel like I was ripping someone off if I charged more than 100 bucks to install a water heater, but then I'm not licensed or bonded so I don't do this for random people, but still, last one I did took less than an hour, it's literally 3 threaded pipes and a flue vent.

Best way to find out what a plumber charges is to call one.

Reply to
James Sweet

It's really easy to take the cost shown on the sticker and extrapolate the actual cost in your area. Cost per year on sticker/cost per therm on sticker = X/Your cost per therm, solve for X.

Reply to
James Sweet

Hi James, In running your calculations, I realized the EF is NOT shown on the energy sticker! But, it can be derived. Is my match below correct?

Given an EnergyGuide sticker that says: "This Model Uses 240 therms/year".

I think we can calculate the ER. Does this calculation look right to you?

240 therms/year * 1 year/41,045,000 btu * 100,000 btu/1 therm = .58

The part of the math that escapes me is why this calculation uses 1,000 times the BTUs per year than the previous calculations. Any idea?

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

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This is all very good but can you trust the figures given by the manufacturers as these are often derived by engineer calculations and marketing guru's and are manipulated to suit their agenda. an example of this is how many people ever get the rated fuel consumption as stated by any vehicle manufacturers, also appliance manufactures have devised ways of confusing the figures to get a better rating that it actually uses. The best way to purchase the water system is to get one that suits your requirements as in size and water capacity. Justy.

Reply to
Only Just

n

bottom line provided you buy a large enough heater the other differences are minor,

operating costs warranty etc,

over the life of the heater, they in any form arent deal breakers. a little shorter life, a little more cost, and as the last poster pointed out manufacturers massage numbers, to make themselves look good. small differences dont matter much

as long as you buy a decent tank you will be satisfied.

The FHR is largely dependent on burner size. the 75K BTU tanks cost more but in the end what everyone wants is enough hot water. no running out please......

Reply to
hallerb

Hi Only Just,

I *think* you *can* trust these numbers (FHR & ER) ... but I'm just going by the written facts. You have the experience I don't have.

The facts are that there are *independent* labs paid to *verify* that these FHR and ER numbers are accurate, for example, OSHA recognizes ITSNA whose numbers I quoted throughout the latter half of this thread.

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Gama says, as of December 12, 2007, "Intertek Testing Services of Cortland, New York
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has been retained as the program administrator and *independent* testing laboratory responsible for conducting efficiency *verification* tests on water heaters" (emphasis mine).

If Intertek is truly "independent", and if they do randomly select units as their product literature says, then I think you *can* trust these numbers.

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

n

No, the tests are done per EPA rules and specs by an independent testing lab.

Now, on the other hand, those tests are performed under a certain set of criteria based on an estimate of how the water heater would actually be used. I would say the difference in how someone will actually uses it in practice as compared to how it was tested, could easily outweigh small differences in the recorded test data under the controlled conditions. I would bet that a heater rated at an eff of .

61 vs one at .58 could easily be a wash or even upside down in actual use. Same thing for the first hour rating.

In other words, over analyzing this whole thing is likely a waste of time. Even the above payback analysis is flawed, because it ignores the time value of money. Laying out $135 today and getting it back over the next 6 years doesn't account for the fact that the money could be earning a return. Or if you put the heater on a credit card and pay interest, even for a short time, and the perceived savings are gone. Take any of that into account and the difference between these heaters shrinks.

Reply to
trader4

I agree. Intertek Testing Services is supposedly independent. If anyone has information otherwise, please post.

Very good point.

Here are the original calculations I posted for inspection: a. Additional cost of more efficient model = $882 - $747 = $135 b. Annual savings of more efficient model = $313 - $288 = $25 per year c. Payback period = $135 / $25 * 365 / 30 = 65 months (5.4 years) e. Overall savings = (13 years - 5.4 years) * $25/year = $190

How would we change these to take into account the time value of money? As always, I'll hazard my math to see if it stands up to scrutiny.

Using the compound interest calculator here ...

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$135 at 5% compounded monthly over the 5.4 years payback period actually costs $176.75 at the 65-month point.

You're right. That's a big difference! (I don't use credit cards so I won't factor in the additional, but huge, credit-card costs if paid on installment!)

Conversly, the annual savings over that same 65-month period is also increased, from $25/year to $26.28 per year using the same 5% interest rate compounded monthly.

This more accurate payback-period calculation then becomes $177 / $26 * 365 / 30 = 83 months (6.9 years).

The overall savings now shrinks a whopping 16% from $190 when not taking into account the time value of money, to (13 years - 6.9 years) * $26/year = $159

Thanks for testing the math. Please let me know what you think of the new, more realistic calculations which take into account the time value of money.

Donna PS Can someone in the field write a calculator to do all this math for us?

Reply to
Donna Ohl, Grady Volunteer Coo

A quick comment on warranty period and the AVERAGE home gas water heater life.

The AVERAGE is exactly that: an average or mean calculation of the life for all units shipped/sold. The real life span is affected by many things, including the water quality/hardness (it consumes the anode quicker), the temperature setting you select (hotter means it builds more internal pressure and you get a shorter life) and the amount of hot water that you use (more cycles of the burner mean a shorter life).

I am on my third gas HWH and purchased the house new in 1991. The first heater lasted about 7 years and the second 6.5 years. I had a 7-year warranty on the tank from Sears and they gave me a replacement free of charge which has been in now for over 5 years. I believe that I will get a longer life this time around since two of my children are no longer living at home.

The bottom line here is that the warranty period may be important depending on your circumstances. It is basically a cheap insurance policy that covers only the cost of a replacement heater. For me, that was important since I do the installation myself, but for someone hiring a plumber, the material cost could easily be less than the labor and associated miscellaneous expenses (permits).

Good luck in whatever you choose.

Bob

"D>>>Heating less water costs less, even with equally efficient heaters.

Reply to
Bob Shuman

You can decide if it's credible but a counter argument to tankless home water heater selection is here

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That web site also provides nice selection and installation advice (with pictures!) for all hot water heaters, including those with tanks and tankless.

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

FOR ME I bought a 50 gallon tank since it was the largest that would fit, with a high output burner to minimize running out of hot water, the warranty is on high output tanks is 7 years. could of got a 12 year tank but I prefered more hot water over longer warranty which is generally pro rated anyway and replacement usually based on list price rather than sale price.

sometimes a tank on sale is cheaper than the same tank warranty replaced.

minor $$$ savings are just that minor, like some fret buying a new tank, to me its a low enough cost, like one candy bar a week who cares,

bottom line i just want lots of nice hot water. costs are way below in priority

Reply to
hallerb

Just to be clear, my research indicates ALL warranties (at least all those from Sears, Home Depot, and Lowes) are really only 1 year labor.

I don't know about you, but, it's not likely I'll be disconnecting my water heater and bringing it to the manufacturer after that one year is up.

May I ask a "real" question?

Given installation is about the same price as the home water heater itself, what do you get for that vaunted 12 year warranty after the first year?

Sure, they'll replace it for free ... but it costs as much to replace as it did to buy so ... tell me please (I'm not being fascesious) ...

WHAT does the warranty *really* buy you after the first year is up?

Donna

Reply to
Donna Ohl, Grady Volunteer Coo

Most plumber wont even park in your driveway for less than 80 bucks.

Reply to
Meat Plow

That's one reason I've never called a plumber. I know most of them aren't getting rich, but still. I've been doing everything myself for so long that I forget sometimes just how much it saves.

Reply to
James Sweet

Well if I understand this right, when you buy the heater you pay for the heater, plus you pay for the installation. For a warranty replacement you pay for the installation, does that not save you the cost of the heater?

My line of thought is that a unit with a longer warranty is likely built better, with better quality components, and thus likely to last longer. Whether this is universally true I can't say, however last time I looked at them, the 12 year warranty heaters did have a nicer fit & finish than the 6 year models, and the price difference was very small. I'll replace it myself if it ever fails, and I'm sure it will outlast the warranty with the soft water we have here, but if it's a higher quality unit I'm willing to pay for that.

Reply to
James Sweet

Tank size is very important and cannot be completely disregarded since it provides the reserve capacity. It is this the tank's storage capacity, in conjunction with the burner size and the EF factor that determines the FHR rating, which determines how much "hot" water you will get before it is considered simply "warm" water. The storage capacity is also very important in regards to determining the physical dimensions of the tank. (I has to fit in the space allowed and the height and spacing of the exhaust flue, water inlet, water outlet and gas inlet will be dependent on the tank's size.)

I already posted my thoughts on warranty as well in a previous reply. The bottom line here is you certainly know more than enough to make an informed choice.

Bob

"D>> bottom line provided you buy a large enough heater the other

Reply to
Bob Shuman

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