Look for any sighs of water and/or corrosion at the top fittings.
Call the landlord.

Call your landlord RIGHT NOW!

Gas water heaters that are set at lower temperatures can have condensation on the outer surfaces of the pressure vessel when cold water flows in replacing the hot water ( when the hot water is used). That condensation drips off as water. Try setting the heater to a higher temperature, at least 10 degrees higher, to see if that stops it.

This post was edited by bus_driver on Wed, Dec 25, 13 at 17:13

Top looks good. I turned temp up. Will report back. No change in amount of water since yesterday. I would prefer to figure things out before involving landlord. I can generally handle most household repairs.

"The water is cold, fills the area around the base, and the lip under the heater itself is full of water".

Hardly seems like condensation. More than likely you are seeing the beginning of a tank leak and there's no repair for that.

If you don't bring this to the immediate attention of the landlord you are remiss in your responsibility as a tenant and it will be difficult to collect for any damage to your property that may be caused when the leak gets bigger. You might even be libel for damage to the premises by not reporting this to the landlord when you fist noticed it.

Could this be a leak? Yes, it could. But there are other possibilities that replacing the heater will not cure.
A leak, especially from a gas water heater, is highly unlikely to be intermittent. Thus the water at the bottom would continue to become greater. Nothing in the description indicates that to be the case.
If the water supply is municipal, this is the time when the incoming water supply gets quite cold, just above freezing. Long hot showers are enjoyed and if a heater is set at 120 degrees, almost all of the flow from the shower head is from the heater. The flue gases from burned natural gas are, by volume, 2/3 water vapor and 1/3 carbon dioxide. That flue gas water will condense upon contacting cold surface--- just like the outside surface of a cold drinking glass.
Turning the heater from 120 to 140 for a few days is a simple sensible test to determine if the water is condensation.
If it is condensation, and the heater is replaced, and the condensation continues-- your landlord will not be pleased at the unnecessary expenditure.

Bus, that's all true and it seems up to the landlord to decide what action should be taken not the renter. At the least the renter should advise the landlord of the problem.

"I noticed water on the platform that the heater sits on. The water is cold, fills the area around the base, and the lip under the heater itself is full of water."

Does the heater stand on legs or seperated from sitting directly on the raised platform?

"If it is condensation, and the heater is replaced, and the condensation continues-- your landlord will not be pleased at the unnecessary expenditure."

Or if he is not informed of the situation and he needs to remove the W/H and replace the platform.

It's not your water heater to repair. It belongs to the landlord. Its your responsibility to call the landlord so he can fix it.

"I noticed water on the platform that the heater sits on. The water is cold, fills the area around the base, and the lip under the heater itself is full of water."

Does the heater stand on legs or seperated from sitting directly on the raised platform?

Directly on platform

Call the landlord. They will have three likely options: 1) order new one, or 2), call a plumber to evaluate (who will probably say it's time for a new one, or 3) leave it alone until it REALLY fails.

"Does the heater stand on legs or seperated from sitting directly on the raised platform?

Directly on platform"

To me, this is a "guarantee to fail" method as garages will inherently have a higher ambient air moisture content, along with the W/H cycles creating the possibility for condensation.

I always set these new heaters on 3 or 4 common brick, which allows an air space under the pan.

Follow-up: New heater being installed tomorrow. Leak has increased and I can see water dripping off insulation.

Thanks for the responses.