Now that you did the water heater flushing for a few minutes once, go back to normal use of hot water for 48 hours except that a few times with a shower or heavy hot usage plus a few hours in between, turn on the hot water (at a faucet) full blast for 60 seconds.

What this does is (hopefully) churn the water at the bottom of the tank vigorously so the remaining sediment redistributes itself on the bottom of the tank.

Add a few hours of no hot water use to let the sediment settle down, and repeat the flush from the water heater drain valve. Then another 48 hour period of normal use, etc.

When you get clear water right from the start when opening the water heater drain you can stop doing the above procedure until 6 months from now.

If you did just one flush from the heater drain valve it is possible you only cut a channel through the sediment at the bottom of the tank. Then you called the job done and called the water heater sediment free.

You will void the water heaterr warranty if you replace the drain valve at the b0ttom

Also you won't be able to compute the needed length for the new drain valve without first removing the old valve because the tank is recessed an inch or so inside the outer shell to allow for the insulation blanket.

A garden hose cap, such as coming with a daisy chainable lawn sprinker, can be used to cover the drain valve it it won't shut off after numerous openings and closings.

 

Yes, those are all good things to try. You have to drain it. Sometimes you got to unplug them to work on them if they really get plugged. An ait tank or air comp helps. I have plumbed an adapter on and force the water out, have back blew the drain to get it cleared. After draining can remove the old element and make a snorkel with shop vac to get it the stuff out. Can even tip them over some , prop up so the bottom is at an angle.

 

Your on the right track, what you need is a full flow 3/4" ball valve and a brass nipple of a length that works for you. 4"-6" usually works.
The plastic nonsense in the bottom of the tank will never let all of the particles out.
Drain the tank, install the brass nipple then a garden hose adapter run the garden hose out side and turn the cold water back on. Run water until you see nothing but water in a clear glass at the end of the hose. May take 1/2 hour.

I do not put any thing into the bottom of the tank, afraid of doing damage. Doubt that the vacuum did any good as the calcium is usually stuck to the bottom and need water pressure to be removed.

The box stores sell ball valves that are not full flow. Do not know why but they do.
Supplyhouse.com

 

I service my heater every 6 months and I noted you mentioned "element" ............ which means you have an electric heater ..... and also means you can do a much better job of maintenance.
Drain the tank and remove the bottom element. In my case I find the sediment is up to the level of the bottom element. ( I replace both elements every six months ) I use a wet vac with a length of automive heater hose to remove the sediment. Be aware you can inspect the condition of your anode rod through the element holes as well .... I just had to replace mine after only three years. I also replaced my drain valve with a full 3/4 ball valve made for flushing ... but my motive is it takes about 1/3rd the time to drain my heater. ( Got mine from Amazon but also available on Ebay )

ALSO ... just to mention.... I have seen articles that the popping noise you describe is caused by air between the element rods and the layer of sediment that forms on the rod itself. I do not experience that because I change the elements.

 

Thanks for all the great replies gentlemen. @SARG That is the brass valve I was looking at. If you look at the listing I do not believe I can use it for my application, which sucks. If you look at my picture you can get an idea. That door closes extremely close to that 'low profile' plastic valve. By the way this little flashlight you can get at Harbor Freight for like $5 is perfect for this. It just barley slips into the top element hole and lights up the entire tank. I also have a telescoping camera I used and was able to look in just below the hole where the top portion of the drain would be and it is filled with huge chunks of sediment. The rest of the tank does not look so bad.

My bottom 'foldback' element was stuck pretty good. I could not even get a screw driver to persuade it down. I had to get a large zip tie and slip it over the stuck portion and pull down on it pretty good to get it to come through the hole. All in all I do not think they look bad but I guess since I am here I should replace them. I am off this weekend but definitely want to get this done and get a hot shower. Are there recommendations on what brand I should use? If possible I would like to find one isn't a foldback element, especially if I can find something that will not sacrifice hot water. I noticed my thermostat is turned up as well. Looks to be about 140 or 145. It is just below the 150 mark.

I sucked so much crap out last night my shop vac got clogged. Hoping it will dry out so I can start again tonight or tomorrow morning. I was worried like @SW Dweller mentioned it would be too hard. I kept having to pull out the piece of hose I rigged to the shop vac and some of the pieces of calcium were so huge they were not even close to fitting through the hole. I plan on taking my air compressor now and trying to open it up a little and displace some more of the calcium.