Water Heater Draining issue

[BBRRaider]

Hi everyone, I've had some difficulty draining my water heater and I'm not too sure how to proceed.

About 6 months ago, my water heater (which I feel like is about 6 year old, I'd have to dig up the paperwork) started making popping noises, so I decided to flush it since it probably has sediment in it. First, I've grew up in this house, but I've owned it the last 10 years. The previous water heater was about 20 years old and sprung a leak one nigh which is why we bought the new one. I mention that because I never heard any popping noises from that one ever. So, I do all the steps (cut the electricity, turn off the incoming water at the tank, open a hot water faucet) and hook up the hose and it is just barely trickling out. After about an hour I'd guess a gallon might have come out. I do open the T&P and that gets things flowing good, I know that's not ideal, but it worked. Probably take another 20 minutes for it to seem to empty from what I recall. Some sandy sediment comes out in the process, probably 2-3 tablespoons worth (from what I remember).

Ok, fast forward to a couple of weeks ago and I hear the popping. Ok, I was planning on doing the draining every six months so I do the draining this morning. This time, I do the steps, hook up the hose and it's coming out, but again pretty slow. Not a trickle, but a weak steady stream. I started this at 8 am and it's been running at the same pace until 5 pm. A descent amount of sediment came out, but I'm at the point where I had to stop since my son has to take a shower for something.

So here's the odd thing. I have the hot water faucet open, which should let air in, I have the water cut off at the water heater, yet I still hear what sounds like pretty loud bubbling or trickling in the tank. When I turn the cold water valve on at the Water Heater (I was doing it occasionally to stir up the sediment), it makes a distinct sound of water rushing into the water heater so I feel pretty sure that the valve is cutting it off, but maybe the valve isn't closing all the way resulting in the water heater taking all day to drain? I guess the only way to verify that would be to cut the main water line off.

Oh, I also occasionally (later in the day) tried opening the T&P valve to see if that would get things flowing (my water heater is in a closet in my hallway, even though I had the hot water tap open it doesn't seem to help with the flow so I was wondering if there could be dips or something in the pipes that create a natural vacuum), but that didn't seem to have any significant impact on the rate of flow.

Or, could there be enough sediment build up at the bottom of the tank that it would take about 9 hours to drain a 40 gallon tank even though it's flowing slowly?

Sorry for the long post, I'm just a little confused as to why I can't seem to get a good drain, except for the first time I opened the T&P valve. Does it sound like the sediment has built up too much? I saw some videos on removing the heating element to track and clean out the bottom of the tank, but I'd have to first get the water heater drained which seems like a chore in itself. Time to call in a professional?

 

[HWSleuth]

The reason opening a hot faucet doesn’t work is there is trapped water in the hot water line not allowing air to get to the heater. The best way to get air to heater is to open the T&PV. When you return heater to service and there’s a drip from the T&PV, lightly tap on the lever. The drip or flow is usually from scale that lodges on the valve‘s seat and tapping it usually removes it. If not, replace the T&PV to be safe.

If the heater’s hot or cold water supplies are flex type, loosen or disconnect one of them. Doing so will let air enter the heater and break the syphion.

If you could remove the heater’s drain valve you can check for scale in the valve or inlet to the valve In the tank. Before you remove the drain valve, if it isn’t already a full port ball valve, replace it with one to aid in future draining.

 

[DIY_guy]

I'd open the T&P valve, but as HW said there may be scaling buildup on it that prevents it from fully closing so that is a risk as it will keep dripping, and if that's the case and tapping on it does not seal it (which I'd not trust over time, it may leak) then you need to replace the valve. Most OEM drain valves are horrible and the smallest piece of scale flake can clog it up and nearly impossible to unclog it without removing the entire valve which obviously is hard to do if the tank won't drain. Mine was clogged and even back washing water into it by hooking up a clothes washer hose from the sink to a garden hose to the HW tank drain valve still did not unclog it. Eventually I had to get a large square 3-4in high storage bin that was low enough to get under the drain valve to hold the water that streamed out after I pulled off the entire valve and then quickly clean the valve and reinstall it. But my tank is in a basement not a closet so I had plenty of room and wet cement floor was not a big deal. As HW said many people will replace the crappy OEM valve with a ball valve that won't easily clog, google it and you'll find it, Amazon sells them like $27. I will replace my OEM valve with a ball valve next time I drain it.

 

[BBRRaider]

Just to reiterate, I did open the T&P valve late in the day to try and break the vacuum but it didn't seem to have an affect on the draining at all. I think unhooking one of the supply lines is the best thing to try. It looks like it has some pipe joint compound on it so I didn't want to unscrew it, but I can.

I didn't mention it, but I do have a brass quarter turn valve (the kind you need a screw driver for), though it's not a ball valve.

I guess I'll wait and see if I get any more popping. I feel like there must still be quite a bit of sediment build up in there due to the slow draining, but I'm not sure how I can clean it, especially if I can't really get it fully drained.

 

[sarg]

Items you need to change or obtain.
I am guessing you have a gas unit because I have read that the described "popping" is caused by a heavy layer of calcium / limescale / sediment in the tank over the burner.
After six years if you have not changed your sacrifice anode rod ........ Your tank is rusting through.
I'm thinking your drain issue is the bottom of the tank is loaded and the crappy stock compression drain valve is plugged. I have seen where you attach a garden hose to the drain and burst water into the tank from the drain to break up the clog ............ It may take time. ( You use a washing machine hose with double female ends to hook up the garden hose )

This website has tons of info:
http://waterheatertimer.org/index.html

 

[BBRRaider]

It's an electric water heater, which I believe can make the same popping nose sure to sediment build up, which I have seen evidence of (I have sediment coming out when draining).

 

[sarg]

If it's electric life is easier.
When you get the water drained pull the elements ( takes an 1 1/2 socket )
I service my tank yearly. Drain the tank ... replace the elements ..... while the bottom element is out I have a dedicated wet vac with a 3 foot length of automotive heater hose that will go through the element hole. You can break up the sediment on the bottom and vacuum it out. The wand can be used to rinse out the insides or you can periodically turn on the cold water entry valve to add flush water.
Most important .... while the elements are out take a flashlight and inspect your anode rod. If it is deteriorated ... replace it ( takes a 1 1/16 six sided socket ).
If you keep a good sacrifice anode in the tank it will last decades.
Here's the page on anode rods :
http://waterheatertimer.org/Replace-anode-rod.html
I recall when we first started maintaining our heater ( thirty years ago ) the sediment was so deep it covered over the bottom low density element ( folded over type ) and it took me twenty minutes to remove it. We also used a length of romex wire and a part of a plastic coat hanger to break up the sediment on the bottom of the tank.

We are attentive to our heater because it's in a closet and a pain to get to if something goes wrong.

 

[Jeff Handy]

You can try a different flushing method.

Turn off the breaker to the heater.
Wait a few minutes for the elements to cool down.

Leave the incoming cold water open.
Don’t shut any valves, don’t open any house faucets.

Attach a hose to the drain valve, and discharge the drain water into a floor drain or a bucket.
If handling hot water is difficult, you can wait a few hours or overnight, until the tank cools down.

The water should be draining forcefully, because you are under full water pressure.
You might have to fully open and close the drain valve several times, to help unclog chunks that can build up in there.

The cold water rushing in will also help to stir up the sediment as it drains.

Operating the t & p valve is always risky, too much chance to cause a drip IMHO.

 

[DIY_guy]

If the T&P valve drips after opening/closing it means it needs to be replaced anyways. Technically you are supposed to test it every year to know it's properly working, so don't fear opening it, just be prepared to replace it if it drips afterwards.

 

[RS]

I have had to run a stiff wire into the drain to break up the clog, and agitate the scale in in the bottom of the tank. When I drain ours I have my air compressor hooked up to the water system, with the regulator set at 60 psi, then the heater drains out quickly with some force.

 

[skeezix]

Well, I might as well chime in here...

I had the identical problem when I replaced my 12-year-old water heater. Closed the fill valve, opened a hot water tap, then opened the drain valve. What a joke! Water just sorta peed out. Then I opened the TP valve. Water still just peed out, then stopped running after a cup or so.

Finally I loosened the supply union and heard a nice long whoosh. The water then came out of the drain and after about 1/2 an hour the tank was empty.

So I think I had a clogged TP valve that wouldn't open. Don't know why opening a hot water tap wouldn't break the vacuum. Go figger...

 

[HWSleuth]

Because water gets trapped in piping between faucet and water heater. The fact opening the T&P valve didn’t allow water into the tank means either the T&P valve was scaled shut, or the drain line from the T&P valve is crimped shut or stopped up. Both very serious situations and need to be corrected yesterday!!!

 

[Twowaxhack]

Check for lime scale on the element, sediment in the tank, low water pressure(30 psi or lower), or abnormal voltages to the water heater.

All can cause noises from an ekectric water heater.