<Water Tank question> Can someone tell me if I need to turn off the gas to my water tank?

Can you call the gas company? I think they would be happy to answer any question concerning a possible gas problem if they are able to advise you from a description over the phone.

When I built my house the gas people turned on the gas to all my appliances not the installer. I don’t know if that matters.

You might try LuckyGuy, he usually knows a lot about stuff like that.

It might well depend on the age of your hot water heater.

My understanding is that all gas appliances have to have a separate ball valve shutoff for each appliance.

There should be a similar valve on the waterline leading into the tank. If you turn that off, all you’ll be without is hot water.

How big is the tank? Mine’s 40 gallon. Unless the leak was really rapid, shutting off the water probably wouldn’t help much, if repair is within 24 hours. I would have to be losing around 2 gallon an hour.

Alternately if you’re worried about water damage, and if you got the water turned off and if there was a floor drain or sump pump near by, you could shut the water off and turn the water heater off. then connect a garden hose to the drain tube and drain the tank.

If you have to replace the tank, consider electric. Much safer from the standpoint of both fire and carbon monoxide release.

Closing the water intake valve on the tank means no water will run from the hot water taps in your home. In fact opening one of the taps and watching the water trickle to a halt is a sure fire way of checking on whether you’ve been successful. The gas valve is closed by turning the lever a quarter turn. notice the direction in the “on” position. At “off” the lever should rest at a right angle to the “on” position. All of this should be on a label affixed to your tank, usually in a stupidly inconvenient place for reading it.

Turn off the gas to the water heater and shut off the water. Then you will still have cold water thruout the house and be able to flush toilets. There will be no hot water. The last time I had a water heater die it was a catastrophic failure and it drained very quickly (we had insane water pressure, but now have a pressure regulator) if it’s a slow leak, you might consider putting a hose on the drain fixture on the bottom part of the tank and drain the heater. It will save the plumber time and allow you to control of where the water goes. Especially if it is a 40 gallon heater. Next time around we are looking at a tankless heater.

Another piece of unasked for advice: if this is your house and the heater must be replaced, don’t skimp. Find someone you trust who knows about such things and invest in a quality heater with a lengthy warranty (10 years & up).

Thank you all. I was able to find the gas valve and the water valve. I was concern about losing water for the house. The tank is 50 gallons. I was concerned about turning off the gas because of the furnace next to it but I see it has its own valve. They share the same connection into the house and it’s getting cold at night.
But mostly I wanted to make sure I turned off the right valve and water connection. There were 3 valves. One like a lever and two like a hose knob. I wasn’t sure which ones I needed to cut off and I didn’t want to cut off the whole house from getting water.
@stanleybmanly That is exactly what I want next. That 50 gallon tank is too large for the furnace room. I want a tankless next. Lived with one in Japan and it was awesome.

Turn off the water, and your tap will still have cold water.
The gas should have a separate cut off.

I have a tankless and I’m luke warm about it. If your water is very hard you have to worry about getting it cleaned periodically. They say every year? Our water here is incredibly hard, but I bought a water softner. I liked the idea of the tankless being more fuel efficient. I’m not sure if it’s worth it financially. I’m not sure how long it takes to recoup your money. Also, with a tank you get hot water for a couple of days when the electricity fails. I think gas tank water heaters you might not need electricity at all? I’m not sure. It would be nice to have some sort of instant hot right at the kitchen sink or places that are very far from the water heater. I hate waiting for hot water, but the tankless doesn’t help with that problem.

Ok, so this is weird. I cleaned out the tank and the plumber came and said it needs to be replaced. He said since it’s a slow leak it we can use the water when we need to shower. So ok. I turned it on and it’s been on for hours and even ran the hot water. No leak. I looked this up and found this article.
http://hinessight.blogs.com/hinessight/2013/01/diagnosing-a-water-heater-leak-for-dummies.html
It’s weird because, whether I use the tank or not, it should still leak if the tank is busted. The outside pipes and fitting were dry at the time of the leak and the water was clearly coming form the bottom. I checked the filter of the tank like they suggest in the article and it is dry. It makes sense that a crack doesn’t uncrack.
Has anyone ever heard of this small well pocket in the hot water heater?

No. But our previous water heater put on the same show to which you’re being treated-a damp spot every now and then out of nowhere. The heater expired some several years (at least 5) after the spots first appeared and I never caught it in the act of dripping a single drop. Through the years, the wife would hound me about replacing the heater, but my view was that it was just a case of “goldbricking” on the part of one of our appliances, all of which have their own personalities. The water tank wasn’t going to get away with “playing sick” on my watch! The wife claims it’s just a matter of my being cheap, but what does SHE know? My advice is to keep an eye on things and notice if the puddle returns more frequently or grows larger over time. But It might be a good idea to figure out in advance where that water is going to go in case the flow increases.

when the tank is cool it might contract and kinda sorta seal, but when it heats up again it will probably open up and seep again. I been thinking about what @Pandora said about her tankless and was reminded of a pretty wicked power outage we had a couple winters ago. We had hot water and the fireplace the whole time, but no lights. With a tankless, we would loose the hot water because it has electronic ignition. Thanks for pointing that out Pandora! I think I’ll keep the tank.

Replace the tank.
It may be that silt has temporarily blocked the leak, but it will not last.

@filmfann , thanks.

Had you ever seen the tank leak before, or are you just assuming that “it must have leaked” because there was water around the base some time ago? The reason I ask is that you may not be dealing with a tank leak at all.

Water heaters normally have (are required to have, anyway) safety relief valves to prevent an out-of-control heater from turning the water to superheated steam which could be a huge risk. So relief valves are provided – and are not normally “used”, because most water heaters work properly most of the time and consumers just don’t care as long as there is sufficient water at sufficient temperature. But sometimes those valves actually function, and actually do release some built-up pressure, including a steam and/or water release. (Those valves can also be set to operate too conservatively – meaning operating too early, when there’s no need for them to function automatically – and can fail in ways that other valves fail in, too, when they simply leak.)

That valve is more than likely at or near the top of your tank and may be one that you’ve identified as “lever action”. (You may not even have identified it as a valve. Here are some example photos from Google.)

Aside from that, however, it is also possible that your cold-water inlet to the heater may simply be allowing condensation to form on the outside of the inlet pipe, which coincidentally finds a drip path to the floor, settling under the heater. In that case the best thing to do would be to apply some light insulation around the cold-water inlet, which just prevents the warm ambient air from contacting the cold pipe, causing that condensation in the first place.

Otherwise, if the tank did leak and you know it, and it’s now not leaking for mysterious reasons, then @filmfann is probably correct in his analysis, and the tank should be replaced or repaired. (There are repair tapes and sealers that will do the job in a pinch and will last for a long time, too. If cost of the repair is an issue a trip to a hardware store may be quite illuminating.)