On 2007-05-29 09:35:58 -0400, " said:

On May 29, 9:03?am, wrote:
On May 29, 7:29 am, Michael wrote:





We have an old AO Smith 40 gallon gas water heater which seems to have
some leakage issues.

We have been anticipating replacing it for some time now but I need
some advice.

There are five of us in the house (including my 15 year old daughter,
who takes very extended showers!)

The current unit seems to poop out after 2 or 3 showers and we will not
run the dishwasher or washing machine in anticipation of showering.

For a new unit, should we go with a larger unit (75 gallon) or are we
better off with a smaller 50 or 65 gallon with a faster recovery time?
What about the "instant," tankless water heaters?

What gives the best performance, balancing efficiency and hot water
availability?

For your 3 stated criteria, tankless wins. The downside is that the
cost of the unit is high and you may need to upgrade your gas line to
the meter to support it. The key question is how much more capacity
do you need from a conventional unit? If you're only just about
running out of capacity on the existing one, I'd go with the 50-65 and
look for one that is faster recovery as well.

I'd also check the flow rates on showers and change the heads if
needed.- Hide quoted text -

- Show quoted text -

avoid tankless, go with a 75 gallon 75K BTU regular tank. just make
certain it will fit in the available space.

tankless sound wonderful till you deal with needing a larger flue,
power line, no hot water on low flow, new gas line and possibly new
meter, you must take into account winter incoming water tempperature,
regular maintence, standard tanks rarely require much of anything,
tankless need a certified technician check every year or two.

a 75K BTU 75 gallon tank will provide you nearly endless hot water
about 4 TIMES your current tank!!!

look at recovery rates this would double your water capacity while
doubling the heating capacity, overall about 4 times your existing
tank....

a big downside to tankless, if something fails you have no hot water
at all, and many a power failure means no hot water at all.

with a regular tank you still have hot water for some quick showers.

Saw this one online.

AO Smith GPHE-50
90% efficiency
Power vent
50 gallon
First Hour Delivery: 127 gallons
Recovery(90 degree rise per hour): 92 gallons
76k btu input per hour

Any comments?