The last time I did this, it seemed to waste a lot of water. So I hit the YouTube. There are conflicting methods there.
One is to shut everything off, open a sink faucet, and then open the drain. That’s what I did last time. Water came out clear. But I had enough knowledge to know the sediment may not have been stirred up. The latest video said to turn the water on after the tank was empty, and the sediment would come out. Which I did last time, but still a lot of water.
The other method I haven’t tried. They said just open the valve and let it run, and the water coming into the tank would stir up the sediment and drain it. Though, I believe the water comes in the top, so how would it stir the sediment? That method would use a lot less water, I think. If it works. Anyone try it this way?
Spotted this… Notice that the dip tube, inlet, drops the flow to the bottom, that should stir it up… In my years (50) here, early days it was a 30g tanker, contractor provided, I may have tried draining it once, but replaced it with a couple of takers for many years, now we’re back to a tank again, a 40g, but unless I hear, see symptoms, I likely won’t bother losing all that water… But if it’s been a while in service, maybe you are due…
For me the operative word is “seemed” – when one drains 40 or 50 gallons it looks like a lot. If you have to carry the water it is a lot. The economic cost for us is about $1.50 per 100 gallons.
Generally speaking if one’s water source is surface water is will be low or at least lower in hardness. And of course folks living in the piedmont regions of the Carolinas have water that actually needs added hardness to adequate clean with soap (as opposed to detergents).
My take on whether to drain or not is based mostly on the water one has. If one’s water hardness is from Magnesium/Calcium and the hardness is over say 50 or 60 ppm (18ppm = 1 Grain) I would never consider it.
Another variable less commonly spoken of is the type of water heater. Gas water heaters likely have the greatest need – the surface temperature is highest and the hardness not only can “bake” on the surface, but that surface is commonly at the bottom of the physical tank. As such the hardness settlement acts like insulation. Electric water heaters have the same problem, but likely to a lesser extent and certainly the sediment will not be insulating the hot surface.
There is yet one more kind of water heater which I suspect is in a whole different league – Tankless heaters. These apparently really do need/require periodic cleaning. In fact some brands actually have a computer chip alert/warning system.
That’s because cold water is denser than warm water, so it naturally sinks to the bottom. If it came in at the top, the entire WH would be “warm”. By putting it at the bottom, you heat at the bottom (gas) or at the bottom and middle (electric) and the hotter water naturally rises to the top, where it is “extracted” when hot water is called for.
So yes, “flushing” the HWH is exactly that. Turn it off. Drain, then run cold water through to stir up the sediments. Costs a buck or two, good maintenance for a heater costing hundreds.
What’s the purpose in draining it if the water coming into the dip tube is under pressure, and basically acting like a jet agitator?
I thought the dip tube was for extraction of water nearest the heat source (bottom). But I just looked it up, and it -as you say- is for the input on cold water. So you have a sprayer, in effect, inside the tank if you open the drain valve.
If you have very hard water (often well water in the midwest), it can deposit solids when heated. Solids can encrust heaters in an electric water heater, cause them to overheat and burn out. They require cleaning. That is rarely a problem with a gas hot water heater. Deposits may make it sound like a steam engine when heating, but still works.
Two things. You hope to get out some of the condensed solids when you drain it, and you hope to agitate more with a jet spray once the water is out. Imagine spraying water on a dish to rinse it off. Now imagine spraying water with the same force onto a full bowl of water. You’ll move some stuff around, but it won’t have the same impact as spraying the bowl with no water in it.
Actually, I was imagining something I used to do when I was very young…blow into the straw that had my drink in it. I sometimes do that today if my beverage has separated, and I want to remix it.
Ours is a gas water heater, but the plumber when he installed it said I should flush it annually. Though…now I’m wondering about the anode rod. That was part of one of the YouTubes I watched.
Ahh, Anodes, Cathodes, Filaments… Reminds me of early tube circuits! I think you could check it before replacing, it’s meant to be eaten away, depending on your water measurements, some to think of it, we end up drinking all that metal in minuscule amounts, I suppose… more if your water leans to acidic side… Never had to change one here, (Northern CA), but we’re on city water, so pretty controlled before it hits the house.. If you are on a well, maybe more important, interesting…
We are on city water also. Plus, it is soft water hitting the tank. Phoenix water is notoriously hard, so we have a softener. Just had it replaced last year, in fact.
One way around consuming that sacrificial rod, generally zinc, into yourself is to not drink or otherwise consume water from the hot tap. I will occasionally fill a pot with hot water to boil pasta or such to save a few minutes. Sometimes I will use hot to dissolve something that will go into the food. But otherwise all the water from my well that gets consumed never went into the hot water tank at all.
Good thought, I do have a hot water pusher pump on my tank to keep the hot water closer to the further sinks, it’s just a valve that lets that pump push some of the hot water hack down the cold water side, but generally a few seconds and the cold is once again cold… Else we had a waiting time for the hot to reach the farther bath sinks, shower…