Sunday, November 04, 2012

"The Personal Is Political," But Water Heaters?

     Wow, who knew having sufficient hot water was a Green conspiracy?  I would've had them down in the "do without" camp, but some folks claim otherwise.

     Whatever. When my Grandmothers got their first hot-water tank for their stoves, when they upgraded from wood or coal to kerosene, it was about convenience.  And when the long, long development of the home water heater finally resulted in a device that was not too likely to make like a rocket or a bomb, they got those, too.  Turn the tap, hot water comes out, how wonderful is that?

     Tam -- and I -- would like to have an infinite supply of hot water, which we don't got.  If I plan to, say, soak in Epson Salts water and then shower afterwards, I have to fill the tub with hot water and add the salts, then wait a bit before soaking and showering, or the water heater will run cold.  Tam observed the procedure and wrote about getting a demand-type "instant" water heater.  (Impractical without a water softener around here, I think -- in Indy, small plumbing leaks tend to be self-healing from the hard water!).  Tsk, you'd'a thunk she was planning to join the Communist Party and liberate the furniture from capitalist oppression.

     Sometimes a water heater is just a water heater -- no, make that "pretty much every time."  Unless it's handwoven by hippies, maybe, and I hear they don't offer much of a warranty.


Dave H said...

My fiancee has an on-demand water heater. She got a kickback from her utility company when she had it installed, and she gets a discount on her bill to boot. All because it's more energy efficient than a tank model. (Tanks burn juice or gas keeping the water hot for when you need it, even when you don't need it.)

I'm not so sure hard water is a problem for a tankless heater. It's just a pipe wrapped in a heating element, really. The only moving part is a flow switch that lights the heating element when you turn on the faucet. Also, you don't have large volumes of water standing for hours at a time dropping sediment like you do in a tank. (When I lived in Ohio I had to replace the lower heating element in my tank about every six months because of it. Those Midwestern limestone aquifers are awful.)

Plus, the only limit on how long a hot shower you can take is your checkbook.

I've looked into getting a tankless heater here, but the trailer's wiring won't support an electric model (they want 100 amps or more) and I don't feel like running a roof vent for a gas unit.

Unknown said...


I looked into a tankless heater a few years back and figured it would pay for itself in about 8-10 years, assuming the price of natural gas stayed constant. Like Dave H says, there may also be tax rebates, subsidies, whatever depending on your state. For what it's worth, most new western European heaters are tankless due to the energy savings, which for some people makes the whole concept socialist, athiest, and immoral -- but then some people are morons.

Drang said...

We looked into getting a tankless when th heater in Alte Schloss Drang went kerflooie in early 2001. At the time, they were pricey and special order. (The plumber said he'd give us a discount in installation, though, because he said he wanted to learn how to do them.) Wound up going with a standard, because they were readily available.
Within a year or two they were stocked at Ace and Sears; Sportsman's Guide usually has a couple of models available in the catalog, as well.

Don said...

I thought she had you at "more computer and radio stuff".

Seriously, the tankless heaters (if gas-powered) do save energy, and provide nearly unlimited hot water if you don't exceed the flow rate. The heat exchanger doesn't get sediment buildup because the water is constantly flowing in operation, and very little is left in the line when it's not.

So, unless the water is so hard you have to replace clogged pipes regularly, you don't have to worry.

DJ said...

I "experienced" a tankless water heater for a week. It was in a rental cabin in the mountains of southern Colorado. Such a machine would have to be vastly better than this one was before I could EVER consider buying one.

The mechanism which regulated the water temperature appeared to be nothing more than a thermostat in the output flow which regulated the heater duty cycle. The cycle period was about three seconds. This meant a shower consisted of alternating very hot / very cold water with a three second period. The only way to smooth this out was to very carefully turn on the hot and cold water at the kitchen sink, the bathroom sink, and the shower, all at the same time, and each at a very critical flow rate. It took a LOT of experimenting to find something that worked.

Yes, really.

Our house has two water heaters, each with 40 gallon capacity and powered by natural gas. Both originals failed after about eight years, one after the other. The first replacement was a Whirlpool (from Lowes), which quickly required the gas regulator to be replaced twice. The second replacement was a GE (from Home Depot), which is (it appears to me) a much better design.

We NEVER run out of hot water, and I'm pretty good at trying to. My wife can fill a large clawfoot type tub and soak in it while I immediately follow with a hot shower. I get tired of the shower long before I run short of hot water. Even with a house full of guests, we don't run out of hot water.

As to it being cheaper to use the instant type because it doesn't have to store hot water, thereby wasting heat through the walls of the tank, I don't buy it. My tanks are cool to the touch when full of hot water; if they waste heat, I can't feel it. I waste more BTU's by running the shower a minute or two longer than I would save by not having a tank full of hot water.

My suggestion is to do what you want, but stay away from Whirlpool tanks with Robert Shaw gas valves.

Jess said...

I haven't researched the difference, but I have the feeling that a tanked water heater becomes much more efficient when the user realizes their use, times the output and the water heater is actually only heating water during a specific time period.

Roberta X said...

My thing about a tanked heater is that it helps heat the basement! We'd probably be fine with a larger tank; what's down there is very short, about a 3/4 size.

It takes high demand to empty it.

Tankless heaters/hard water: that's design-dependent and the more efficient the heater (lots of surface area contact between heater and water pipe), the smaller the cross-sectional area of each pipe. So a really super-good one...would be super-bad, too.

Leatherneck said...

We've always had tanks. In a long-ago house I had a now-funny incident. During the night, a thermostat stuck "on". When I peed and flushed in the early morning, the toilet exploded with steam. Being a quick young Marine pilot, I ran outside (naky-naky, but you don't need to know that, so forget please.)and turned on the outside hose. The pressure ruotured the hose, but prevented what I'm sure would have been a fearsome rupture of important parts in the utility room.

We have a Rinnai tankless powered by propane at our soon-to-be ritirement cottag down at the Chesapeake. With the thermostat set at 120 degrees it will fill a bathtub full that's too hot to get into fast. It provides sufficiently fast hot water at the kitcen sink to rinse/wash. I the big walk-in shower we find it not quite hot enough whan we shower. I may turn it up 10 degrees.

I miss the warmth in the basement. I may install a fireplace down there.

The bottom line is that during the week or two between our visite we spend nothing for maintaining hot water.


Leatherneck said...

Sorry for the typos.

og said...

New tanks (I replaced my 30 with a 40) are often what they call "Rapid Recovery" in that they "Re-heat" more quickly. Also, an oder one especially a small one can be so inefficient as to warrant replacement before six or seven years. Especially with hard water.

Why no softener? Just no room? A softener is cheap and makes a whole lot of difference.

DJ said...

Our house had an interesting flaw in the plumbing.

The water line comes in at the northeast corner of the house.

One water heater is near the southeast corner, in an outside-access closet that bumps into the master bedroom closet. The other water heater is in a closet of the garage, about fifteen feet from the west wall of the house. Each water heater feeds a manifold, which distributes hot water to local bathrooms, the laundry room, and the kitchen.

The two hot water manifolds are tied together by a line connecting them. This is not bad, as each end of the house gets hot water quickly, but both water heaters feed the whole house, so it's difficult to use it all up.

So far, so good, right?

Nope. Water flows from high pressure to low pressure.

When we turned on the hose bibb at the west end of the house, the water pressure was progressively lower toward that end. Cold water would flow into the east water heater, pushing hot water out of it and into its hot water manifold, then to the other hot water manifold, and then into the west water heater (flowing backwards), and finally out of it into the cold water manifold. So, we had very hot water coming out the west hose bibb. It's not good to water a tree with hot water. In fact, we had difficulty getting cold water anywhere in the west end of the house.

It took a bit of work to map it out, but the fix was easy. I put a check valve at the inlet to the west water heater, which prevents it from flowing backwards into the cold water manifold. Now we get hot and cold water where we should.

Roberta X said...

Og: actually, I don't much like softened water. It tastes funny and feels too slippery in the shower. Idiotic, I know, and good water does amazing things for my hair, but I just can't get used to it.

Roberta X said...

TC: OMG! With a story that good, nobody notices a few typos.

wrm said...

As I see it you have two options. A large geyser, or a smaller one running hot. Of course, the hotter you run it the greater the delta T the more heat loss to the environment.

Over here, we had some shenanigans with a democratically elected government and economic empowerment with one result being lots of money spent on young upcoming execs and little money spent on maintenance. So when the cows came home to roost, electricity was suddenly an issue. To save same, we have a magic elf box called a Geyserwise. Allows you to turn the damn thing on and off and to different temperatures different times of the day -- all very wonderful, really.

Except the eco nazis have decided that the geyser should not run hotter than 65 C. I run our 250 liter unit (what's that, about 50 gallons?) at 75 to cater for three wimminfolk. Now, I can't. More hot water, less cold water, and the thing runs dry more quickly.

Of course it's a thermocouple, nothing a series resistor of two or three hundred ohms won't fix.

Is there a reason you can't crank your tank temperature up a bit?

Roberta X said...

I run the tank way hot already, is why. :)

aczarnowski said...

This guy on the internet's opinion is you might need a new tank.

We replaced ours about five years ago and the amount of buildup inside the old one was amazing. A real PITA to get out of the basement since the drain valve had closed up so it still held a bunch of water.

Sounds like your water is even harder. I bet that tank is even smaller than its small outside dimensions would indicate.

As for tankless, my Dad had one when they first came out for space reasons. Neat idea. I get why they would be good things. But it's going to take a lot of first hand, amazing, experiences with new ones to wash (heh) the memory away of wild temperature swings and cold water with every initial valve opening.

og said...

Hard water will cause even your tank heater to deteriorate faster. And a water softener isn't a binary thing, either, at least not anymore. You can still leave the water about two grains hard and it'll feel a lot less slimy, or not slimy at all, and damage your pipes and heater less. And a separate, filtered but not softened drinking/cooking water tap on the sink would be simple to install, as I'm sure you know.

You might have to change your heater anode about a year more frequently but you should be doing that anyway with hard water- hard can cause a heater anode to passivate and not do it's job at all. You ought to yank it once a year for inspection just on general principles.

If you choose to replace the heater- which is an excellent idea, make sure you get one still short enough to allow you to pull the anode, or get one of the ones with short anodes.

Roberta X said...

I may need a new tank, but the thing is less than five years old. And it is quite small.

og said...

I bet its cloggy. Have you ever drained it? When we replaced our last one we ended up with about 14 inches of sediment in the old tank (had to slice it up to get it up stairs)