Unused water heater, leave full or empty?

You could get a water heater that's being replaced before it bursts. Just add a valve on its inlet side so there is no pressure on it when it's not in use. It should last a long time without constant pressure on it. If it does leak, you're right there.

I got nowhere by asking a plumbing supply house this question. The owner thought it was a good idea but couldn't find an inexpensive tank in his catalog.

The two best possibilities I can think of are a bladder tank for a well and a water softener tank.

Which is why I said that energy savings occur during summertime through a reduction in AC usage.

We have something like 150 ft of 1 inch black plastic water pipe in a coil (maybe 3 ft in diameter), hanging on the wall downstairs before the toilet supply. Does wonders in the summer time when they would sweat otherwise. Used to have a galvanized water pressure tank for same years ago but due to hard water it developed a lot of sediment. So far the coiled up pipe seems to be working okay, maybe 20 years now.

Putting that coil outside in the sun would be even better, in the summer. Solar on the cheap.... Or in a black box, covered by glass..... really good solar, on the cheap....

Toward the purpose-made tank Q: An old compressor tank, 30-50 gals? Or smaller ones in series? Even propane? Altho the fittings on propane are an experience to remove.... May want to paint the interior first.

Rust and what the anode is there for are two seperate things. Rust involves oxygen combining with iron. The sacrificial anode involves two dissimilar metals in an electrolyte ====================================================

A good observation, BUT the (dissolved) oxygen would/should combine with sacrificial magnesium, zinc etc first, as well.

Magnesium, zinc, alum appear not to "rust" because the nature of those oxides is *mechanically* stable, whereas iron oxides are not, constantly exposing more fresh iron, ergo a deterioating process.

I believe he said "reduce summer time costs". And it does do that since ground water and city water are usually a lot cooler than summer air temps.

I run two wh in series with the 1st one on a 30amp switch in the hall. When I anticipate guests or otherwise needing extra hw I just turn it on. ==============================================

Staged water heating.... what a neat idear!!

to get hot water in a toilet?

Certainly..... who wants cold water splashing on their ass?? sheeesh.....

There are actually mixing valves to mix hot water from the water heater with the water supply to the toilet to keep the toilet tank from sweating. ^_^

TDD

Sounds like bidet temperature.... lol

You mean one of those French made pet water fountains in a bathroom. ^_^

TDD

Also a hillbilly water fountain/emergency eyewash.... A few here.... George, Attila, JoeBoi -- will proly further misconstrue it, and use it to pressurize demselves, shooting off the bidet like a water rocket.... proly up to the stratosphere.

Shouldn't you use ice water for those?

I suppose it depends on whether or not your dog likes ice water? O_o

TDD

You've never seen a dog go berserk over ice cubes? Or give you a dirty look, because all the ice has melted & the water in their bowl is warm?

The Rotthuahua that adopted me doesn't like the cold. Actually her name is Sandy, a Red Chihuahua who thinks she's a Rottweiler and her little mouth is so tiny, a normal sized ice cube is too big for her anyway. Heck, the body temperature of those barking rats is normally ±101°F and it's surprisingly cold at floor level which is why Sandy is always finding something to burrow under like a coat, towel or blanket to stay warm. ^_^

TDD

Tried that with my dog Picked out the ice cubes and dropped them next to the bowl and ignored them while they melted and made a puddle.