40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

[Thomas G. Marshall]

Ok, our 40 gal gas water heater is failing. About 10 years old, which I hear is ok.

But every time I talk to someone about their 40 gal water heater, they all complain that they run out of hot water (comparable size homes and kids).

Bur our builder (and all builder's we spoke to when looking to build)

*insist* that 40 gallons is enough.

But we were always worried about running the wash or dishwasher before showering, or two long showers would result in the 2nd losing water. Complete with those water saving disks etc.

1. Is 80 gallons overkill? Perhaps I'm reacting viscerally.

1. Am I going to notice a large gas usage increase?

2. Are there rules in place limiting the water tank sizes?

1. Are there any particular brands to look for or stay away from?

I'm sorry for the barrage of questions.

[dpb]

Thomas G. Marshall wrote: ...

In my experience, yes; but everybody is different. We raised four kids and don't recall running out of hot water being a significant issue.

Well, certainly it will go up -- how much will depend on how much more hot water you end up actually using.

Some jurisdictions, possibly altho I've not heard of it doesn't mean there aren't...

No data...

Comments --

1. There's a middle between 40 and 80, too. What about 50/60???

1. If there's a particular bath that tends to be the problem area, might consider the on-demand solution for the overloaded area.

2. Depending on house layout, two smaller each located strategically might be a better solution than the single larger, too...

[Glenn]

When I had two daughters home, I had two 40gal set up in series. They make a 60 gal but 2 - 40's probably would be cheaper.

[Thomas G. Marshall]

Glenn said something like:

Another question that has always bugged me raises in me noggin.

What happens when half a tank is used up? Does ice cold water rush in and cool everything down? Is it thus better to gang two together somehow to have the 2nd take over when the first is refilling?

[RicodJour]

Instead of replacing the old with a newer version of the old, you may want to look into a tankless water heater instead of keeping that 40+ gallons of water at ready-to-be-used temperature 24/7/365 when you really only need the hot water for _maybe_ an hour a day. They've been in use around the world for decades, but are just gaining momentum in the US. Here's one link:

I haven't read through that link, but it seemed to hit the high points and will give you an overview - from there it's up to you and your finely honed Google skills.

R

[Jeff Cohen]

Cold water sinks so it pushes the hot water up, although you will get some "warm" water before cold as the hot water runs out.

I would agree that 40 is enough most of the time but you will run short every now and then. I can't imaging a 60 gal not being adequate for you. The idea of 2 x 40 gal is interesting, but I suspect it would use more energy than 1 X 80 check the ratings, certainly more than 1 x 60 gal.

[Bill]

Tankless is the way to go. Just ask yourself, do you keep your auto running in the driveway so it will be warm when you get in it?

They say tankless is 80% more efficient than an electric tank. That one is more expensive, but it recoupes in cost in two to three years.

[mike]

Spare us the tankless marketing bullship. Standard water heaters DO NOT run constantly. They are well insulated and have a large thermal mass of water inside.

When tankless salesmen feel the need to trot out BS like that, it makes me distrust any further "data" they want to push.

[RicodJour]

No, they don't run constantly, but they do maintain a large amount of mass at a substantially higher temperature with relatively little insulation. There's only one way to do that - throw money at it. The standard water heater tank doesn't have a setback or vacation setting, so it maintains that higher temperature regardless of the amount of hot water actually needed, time of day, etc. Tankless is a superior system for almost everyone. I don't buy anything based on what a salesman or marketing department states without performing some due diligence and investigating on my own.

R

[Bill]

Salesman I'm not, someone who likes to save money, I am. I'm sorry you are that naive to technology.

Spare us the tankless marketing bullship. Standard water heaters DO NOT run constantly. They are well insulated and have a large thermal mass of water inside.

When tankless salesmen feel the need to trot out BS like that, it makes me distrust any further "data" they want to push.

[Phisherman]

Sounds a lot, but maybe that is what you need. Teenagers use the most hot water for some reason.

Maybe. If you have more hot water, there may be less effort to conserve.

No. But 80 sounds large. A tank with a different height may present some installation issues, so allow for more time.

Stick with well-known brands. I added a thermal blanket to my water heater, plus insulated all the hot water tubes. I set the water temperature to 125 degrees. Anything lower than 120 can grow bacteria. Flush your tank twice a year and it should last longer than 10 years.

[Blattus Slafaly]

Oil fired tankless is the way to go. All the hot water you want, never run out and it stops running just as soon as you cut off the faucet. I know because I had one.

[Percival P. Cassidy]

ISTR that the standard capacity in Australia was 60 gallons, with 80 gallons as a common upgrade -- and remember that these are "Real gallons," each consisting of eight 20-ounce pints. The one already in the house we bought in the US Midwest, however, is 50 (mini-)gallons.

I don't know how the various brands rate here in the USA, but Rheem was common in Australia. When we built our house in Australia, however, we used a local (I mean really local, not marketed outside that State, AFAIK) brand that had a 25-yr warranty. One day I was wandering through a shopping mall and got accosted by the salesdroid at a Rheem booth who asked me how old my water heater was; when I told him "12 years," he said, "Oh, so you'll be needing a new one soon"; when I told him the brand I had, he said, "Oh, then you won't be needing a new one for a long time yet." IOW, widely advertised brands aren't always the best.

Perce

[Stormin Mormon]

Sounds a lot, but maybe that is what you need. Teenagers use the most hot water for some reason.

CY: Consider a low flow showerhead in the kids side of the house.

Maybe. If you have more hot water, there may be less effort to conserve.

CY: Everyone will say "Hey, we got plenty... "

No. But 80 sounds large. A tank with a different height may present some installation issues, so allow for more time.

CY: I know of no rules.

Stick with well-known brands. I added a thermal blanket to my water heater, plus insulated all the hot water tubes. I set the water temperature to 125 degrees. Anything lower than 120 can grow bacteria. Flush your tank twice a year and it should last longer than 10 years.

CY: If you turn the temp up, you risk scalding. However, a hotter temp means the kids have to dial in more cold, so the water in the tank lasts longer. A hotter temp and a "tempering valve" is an option.

[Stormin Mormon]

One WH feeding the kids shower, other WH for parents and kitchen?

[Stormin Mormon]

I think that's a false comparison. The only time the burner or heater runs, is to replace lost heat. Heat lost from the tank. That's lost through one of several ways. Depending if it's gas or electric or fuel oil source, different methods of heat loss.

[mike]

You're the one who thought that standard water heaters run continuously and that tankless are 80% more efficient than tanks! SNORT.

Maybe you should listen to someone besides your tankless salesman:

But if you want spend dollars to chase pennies, more power to ya.

[S. Barker]

the best solution really again falls back on supervision and discipline. (something parents don't think they have to do anymore) Make rules and enforce them. Teenager showers are 5 minutes long. Period. No hot water problem, no outrageous water bills, no septic problems. (for those on septics). We raised 2 boys and had countless others living with us over the years and made do just fine on a gas 40 gallon unit.

and the tankless boys can stick them. I like HOT water. Not lukewarm water.

s

[trader4]

Before concluding that 40gallons is the problem, I'd check the shower heads and flow rates. You may find that reducing the shower flow a bit means you will have enough hot water from a 40 and save energy too. Also, it's possible the existing one has some serious problems. If it's full of sediment, has a broken dip tube, etc, it may not be performing anywhere near what a new one is capable of.

Check the first hour rating on the ones you are considering. That'a a good indicator of how much water they can supply in typical high demand hour.

If you do decide to go larger, I'd think a 50 with a good first hour rating would probably be enough for most families of 4.

As others have pointed out, you can also consider tankless. Main issues there are unit and installation cost, which can be higher depending on existing gas lines. The TL needs a much larger gas supply.

[hallerb]

regular 40 gallon hot water tank BTU vary anywhere from 34,000 btu to

75,000 btu. the higher the BTU the better.

Because we ran out occasionally we went from a 34,000 BTU 40 gallon tank to a 75,000 BTU 50 gallon tank. I wanted a 75 gallon tank but it wouldnt fit the available space between toilet and furnace.

Tankless tends to be a hot topic here........ from inadquate heat, = cool showers if you live in areas that freeze in the winter, no hot water at all in a power failure, if the tankless uses line voltage to operate, no hot water with valve just open a little, super expensive install, needing new gas line and occasionally a new meter. teenagers given unlimited hot water might live in the shower. expensive service, tankless are complex and require occasional service, standby losses in current tanks is actually low, and stanby losses help heat your home in the winter, so most of the heat isnt really lost. life is full of sytandby losses, tv, cable boxes clocks etc etc. anything that draws power when not in use is a standby loss......

your old tank is probably full of sludge decreasing its hot water ability.

a new tankless will cost a fortune.......... 3 to 4 times a standard tank which is highly reliable.

so lets talk tanks

upgrade from your old 40 gallon probably 40,000 btu to a 75 or 80 gallon 75,000 btu will likely give you about 4 times or more your current hot water capacity. and in its life probably never need service

you double the gallon capacity and double the burners BTU rating, roughly 4 times the hot water.

no more cold showers:)