Water Heaters - Water going out, but where?

Last week my gas water heater started making a sound like it was refilling, even though we hadn't used any hot water in hours. It was exceptionally cold that weekend, so I ignored it. But it's still doing it. It's in a semi-heated basement laundry room. It sounds like running water for 10-15 seconds every couple of hours. The water meter runs when it makes the noise. If you shut off the cold water intake valve, it stops. So water is definitely going in, but I can't find where it's coming out. All of the faucets are off with no drips. I can see all of the hot water piping as it leaves the heater and enters the floor upstairs and then from upstairs where it enters the faucets -- there's no leaks. Whirlpool helpline insists there's a leak. I checked the TPV valve, it functions normally. The water remains as hot as normal -- it's set on the warm setting. The water heater is a little over a year old and is supposed to have a propeller inside so I don't need to drain it.

Also last week, I had a mineral buildup in my dishwasher. I ran the cycle twice, and it just got worse. I've since ran a dishwasher cleaner through, and it cleared up, although I did pull some lint like substance out of the top spinner wand.

Should I drain it? Any other ideas?

tkrynearson, Welcome to the DIY Forums.
That is certainly a strange problem. I will think on that one,but, in the mean time check your washing machine. Thats the only hot water user I can think of that may be leaking on an intermittant schedule. If the fill valve is bad, it may be opening slightly and then closing again. You could also turn off the hot water valve for the washer and see if the noise and water usage continue. One other culprit could be the dishwasher if you have one. Good luck.

I've checked all around the dishwasher and washing machine -- no standing water inside, nothing around it. I've checked the toilets, sinks and showers as well as the perimeter of the house. Every wall, every floor is dry inside and out, upstairs and down.:wall:

I drained the hot water heater last night and discovered my 40-gallon tank is only holding 10ish. At least, that's all that came out and when I went to refill, it only filled for 5-10 seconds.

Ideas?

Did you open a hot water faucet while draining or open the handle on the relief valve? If not, you may have pulled a vacuum on the tank due to no air to let it drain.

I followed the instructions in the owner's manual (turn off gas, open hot water faucet, turn off cold water into it, open drain, flush, close drain, refill tank, light pilot. I opened the hot water faucet for my washing machine -- why waste hot water -- and it barely put any water in it. Then I turned off the water into the heater and opened the bottom outlet and barely a trickle came out. I turned the cold water back on and let it flush out a bit then sealed it all back up.

Check the inside of your hose connections to the washing machine. If you had mineral buildup in another appliance, then its possible that these hoses are partially blocked. So if the hot water side is partially blocked, your hot water heater will not drain because insufficient air is not getting back to the tank. Disconnect both hoses and make sure they are clear. Most hoses that I have seen have metal filters in them and they may be clogged. Check both ends of the hoses.
If ok, connect the cold water hose and leave the hot water hose disconnected. Hook up a hose to the drain and open the drain valve. if it still does not drain, then slowly open the t & p valve located near top of tank, while holding a bucket under it.
You may or may not get any water from it depending on the level of water in the tank. Now if you still do not get water draining up to 40 or more gallons, then you have a serious clog in the hot water heater. Hard to believe when your heater is a year old but possible if your water supply has a lot of minerals in it. Then you will have to consider installing a water treatment system.

rjordan, do you realize you are responding to a post from last february??

Opp's!
Thanks, I'll check the date next time.