Help with new Hot water heater

May 29, 2007 22 Replies

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.

How well do the tankless work in a northeastern climate though?

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.

It's just a matter of how big of a unit you need, how big of a gas line, and how much you want to spend. There are spec sheets readily available online that show the flow rate vs water temp rise the unit will support. No question gas ones can work, electric is a diff story.

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?

Go with a 35 gallon quick recovery, preferably gas fired. That will get the teenager out of the shower when she runs out of hot water, and the next shower will be ready to go in short order.

Of course you could try setting limits and actually directing your teenager's habits. O, I forgot. It's no longer a parent's right or duty to direct they must just suffer whatever the princess inflicts on them.

"Dave"

How about you save your crap for some other newsgroup or stick to subjects on which you actually can provide intelligent comment.

Yep. Ignore the real problem and attack the messenger. The princess rules in your house too.

how about a link to it online. do you need a power vent? is the current tank a power vent?

home depot and lowes sell high recovery tanks up to 100 gallons,

compare current tanks first hour and recovery with perspective new tank .

I like long hot showers thats why I upgraded to a 50 gallon 75K BTU tank here, a 75 gallon wouldnt physically fit the space really glad I did this we al;mostr never run out of hot water unless both washing machines and dishwasher is all running at once

appears a princess rules in YOUR home too.

often its easier to accomodate people on stuff, i dont know about you but I pick my fights...

hot water? not worth the effort..

Michael,

How do you heat your house? Have you looked into adding a unit to the heating systme for heating your hot water? For instance, adding an indirect water heater or booster tank? If your heating system is old you may want to look at the overall picture of both heat and hotwater. Also, you may want to consult your local heating contractor for reccomendations.

-paul

Would it also be worth looking into a "point of use" heater, either tankless or with a small tank, for the shower? The shower seems to be the problem area.

A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail?

We have a NG fired, forced hot air system (High efficiency, direct vent/sealed firebox). The furnace was just replaced about eight years ago, A/C coil and compressor replaced a year after that.

I went through this a few years ago, only 4 in the house but 2 of them teenagers. I went with a 50 gallon gas-fired conventional water heater and it has served us well. No hot water availability issues in practice, although I suppose in theory it could happen through coincident heavy usage. That is, I wouldn't guarantee that it would never happen, but in practice it has been fine. Your old unit may be limed up and in fact have less capacity than its rating.

When my daughter took showers I used to shout through the door, "leave some water for the fishes in the sea."

Translation: I have no influence over the princess. She rules the house.

I bet dave has a BAD attitude because kids ion his house have stream rolled over him, he takes out the aggression by finding fault here.

Now take for instance a home with a 60 amp main breaker.

When too many people turn on appliances do you complain too much power is being used? or do the right thing and upgrade to 100 or 200 amp service?

In daves world power would be rationed. Turn on hairdryer 4 minutes, now hair dryer off curling iron on 3 minute max, hey want toast OK you have 2 minutes:)

You may be trying to solve the wrong problem.

Replace the shower head with a hand-operated sprayer on a hose. Then everyone can take a "Navy Shower:" Wet, lather, rinse. Total water usage,

1.6 gallons.

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