On Feb 10, 9:38 pm, "Donna Ohl, Grady Volunteer Coordinator"
Get a heater with the same gallons as you currently have, and as high
an efficiency rating as possible, go for at least a 5-year warranty.
Get a unit that is exactly the same outside dimensions so the piping
does not have to be changed and find a reasonably handy neighbor to
put the new tank in. It should take less than 30 minutes to do the
entire switch-out if the old and new tanks are the exact same size.
Compare prices on a cost per year of warranty coverage, I have seen a
lot of heaters that go bad within a year or so of the expiration of
the warranty, so cost per year of coverage is a good comparison
criteria. If you have the room, adding a fibre-glass water heater
cover over the new tank will improve the heat loss and thus raise the
efficiency. Don't obcess(SP?) about this, it isn't worth the time and
H. R.(Bob) Hofmann
On Sun, 10 Feb 2008 21:20:35 -0700, Rick Blaine wrote:
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.
A quick comment on warranty period and the AVERAGE home gas water heater
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
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
Good luck in whatever you choose.
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
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
bottom line i just want lots of nice hot water. costs are way below in
On Wed, 13 Feb 2008 08:34:00 -0800 (PST), firstname.lastname@example.org wrote:
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?
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
I read the article you referenced at
It doesn't say WHERE the 41,045 BTU number cames from.
What is this "magic" number of 41,045 BTU?
The right reference is
The document that has that calculation is
But it still doesn't say where the "magic" 41,045 BTU comes from.
On Wed, 13 Feb 2008 11:53:00 -0800 (PST), email@example.com wrote:
On Wed, 13 Feb 2008 11:53:00 -0800 (PST), firstname.lastname@example.org wrote:
Whatever magic it is, googling for 41045 BTU gets *lots* of related PDFs!
Residential ACM Manual: Water Heating Calculation Method, page 8
The standard energy in the hot water delivered, 41,045 Btu/day.
Comments on Energy Star Ratings of Home Water Heaters, Page 5
Using the formula: 41,045 Btu/EF($/Btu)*365
ENERGY STAR Residential Water Heaters: Analysis, page 10
Energy consumption estimated using the DOE test procedure.
Based on the following formula: (41,045 BTU/EF x 365)/100,000
LIFE CYCLE COSTS AND SAVINGS FOR WATER HEATING SYSTEMS, page 3
The annual delivered energy is 14.98 MMBtu (41045 Btu/day).
OPERATING GUIDELINES AND STANDARDS FOR WATER HEATING SYSTEMS, page 32
Total Energy Draw 43.302 MJ (41,045 Btu)
Consumers Directory of Home Water Heater Ratings, page
Using the formula: 41045 Btu/EF($/Btu)*365
Calculating water heater costs for meaningful comparisons
You need to know the unit cost of fuel
365 × 41045/EF × fuel cost (BTU) = estimated annual cost of operation
365 × 0.4105/EF × fuel cost (therm) = estimated annual cost of operation
Review of hot water heaters
365 X 41045/EF X Fuel Cost (BTU) = estimated annual cost of operation
365 X 0.4105/EF X Fuel Cost (therm) = estimated annual cost of operation
On-demand water heaters, page 8
.41045 x cost per therm of gas x 365 / EF = yearly cost to operate
I would guess any engineer should be able to tell us what this 41,045 magic
number really is.
On Sat, 16 Feb 2008 22:57:32 GMT, Donna Ohl, Grady Volunteer Coordinator
I'm surprised a chemist or engineer isn't on this group.
I think this is the fundamental answer!
page 11, Water Heating Calculations
43,302 kJ/day is 41,045 Btu/day is the energy delivered to the hot water
load per day
And, this one says most plumbers don't understand the efficiency factor for
home water heaters
Residential Gas Water Heating:
Program Design & Specification Considerations, page 6
Annual Savings (Therms/year) is based on the DOE Test Procedure:
On Sat 16 Feb 2008 23:08:42, Donna Ohl, Grady Volunteer Coordinator
You tell 'em Donna. Show them you knew the answer all along.
Poor " email@example.com" and others like him now don't know what's
Nothing like reeling in a very long fishing line that you've
carefully laid out. Good one!!
On Wed, 13 Feb 2008 11:17:11 -0800 (PST), firstname.lastname@example.org wrote:
I think it's the assumed amount of BTUs an "average" household uses in a
I'm sure there are math majors out there in the crowd who could tell us if
that assumption is true given the formulas previously provided.
Sears 33154 (marketed as Kenmore but made by AO Smith) FHR EF=0.63
(41,045 btu/0.63)($1.21106/therm * 1 therm/100,000 btu) x 365 = $288/year
Home Depot 183-717 (marketed as GE but made by Rheem) FHR EF=0.58
(41,045 btu/0.58)($1.21106/therm * 1 therm/100,000 btu) x 365 = $313/year
Are any mathematicians out there who can tell us the units on the 41,045?
If you do self installation, like most of the audience on your target
newsgroups, then the warranty means a big deal. If you pay someone to
install, then it may not be as important, especially if the design,
materials, and construction quality is identical.
having only 1 heater leak before the warranty ran out, and as far as i
know its still a pro rata warranty....
number of installed months, vs number of warranteed months, gives a
percentage, thats then applied to a brand new similiar heater at full
on that one heater the sale price was less than the pro rata price,
kinda mad i bought my new one somewhere else........
warrantys are sales tools, they rarely help the purchaser much. wheres
your original invoice? company like sears might no longer be in
business in 8 years.........
just look at all the retailers who have goine out of business over the
a warranty from builders square or hechinger isnt worth the paper its
the BTU # is from the manufacturer, they vary from under 30,000 BTU to
75,000 BTU on my current tank.
higher btus cost more to build, better stronger burner and heavier
tank to take the added heat.
I can't say that I know what the 41,045 BTU is in the calculation but
it can't be different for different gas burners because it's the same
number no matter what gas heater you use.
So it must be some kind of other "magic" number.
You keep all of that stuff, and not just in case you ever need to invoke the
warranty - you keep it for tax or insurance purposes.
You keep this stuff in a file folder in a drawer - it takes a few second to
put it there when you buy something new. Or in the case of something like a
water heater, you put it in a plastic bag and tape it to the appliance.
In my case, it was not pro-rated. I was given a new gas HWH by Sears to
replace the one that developed the small leak within the 7-year tank rust
out warranty period. I did need to bring them the old tank though, which
was not an issue.
On Wed, 13 Feb 2008 19:33:41 GMT, Bob Shuman wrote:
I've learned that I agree with you.
The warranty is for the fire-and-forget type of homeowner.
The one who doesn't flush twice yearly, who doesn't add the second anode,
who doesn't replace the anode after a few years, who doesn't add the ball
Even then, the owner with the warranty has to bring the soaking wet heater
in the back of their car in to the manufacturer after their 1-year is up on
their supposed 12-year warranty - or else pay as much for the plumber to
visit ($400) as the heater cost in the first place ($400) to obtain the
Some deal, that 12-year warranty!
Or am I reading it wrong?
You're pretty much right, although you still might find that within a
particular model line there are some quality/efficiency/construction
differences between the 6-year and 12-year models. you'll have to
evaluate those on a case by case basis though.
replace "roosters" with "cox" to reply.
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