Water heater with a mystery leak

Curb71

I have a 40 gallon gas kenmore water heater installed july 15th of 2011. I just bought this home in january so all I knew was there is a new water heater.

Yesterday I notice the drain pan is half full of water and has been leaking over onto the wooden platform and through the pvc drain line.
I soak up all the water so the pan was almost dry and was checking for leaks.

I put a glass under the t&p drain line and hours later the cup was empty but water was back in the pan.
I checked the flexes on top of the tank and everything is clean and dry up there.
I ran my hand along the base of the tank and its smooth and dry.
I checked the t&p valve and it looks clean and is dry.

Where could this leak be coming from or what else could I check to find out where this is coming from?

Lightfoot

is the ceiling dry?
sometime the roof will leak around the vent pipe and run down the heater.
if it hasn't been raining, then mark that off.

Curb71

yeah, roof is dry.

joecaption

Gas or electric?
If electric, cut the power and remove the cover plate , check for leaks around the elements and that general area.

Curb71

Its a 40 gallon gas.

ben's plumbing

did you check the drain valve...sometimes they leak when the tank is fired....thermal expanison causes pressure inside tank...maybe valve is leaking at alittle higher pressure...but not high enough to trip t p r valve..

Michael Thomas

Is the heater properly sized for the demand - an undersized heater can experience excessive condensation.

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Curb71

I didn't check the drain valve. I don't have a thermal expanison tank so that could be the problem. My pressure regulator is set at 80psi. The t&p valve is no leaking abs I've had a glass sitting in the drain pan under the copper t&p drain line and the glass is empty but the pan is filling up again. I'll move the glass under the drain valve to see if the drain valve is leaking.

Curb71

Yes. It's a 40 gallon tank on a 2 bath home and I live alone.

ben's plumbing

you should have expanison tank on your system reguardless..

Curb71

I thought a thermal expanison tank was only necessary if I had a check valve or back flow valve in the system.

ben's plumbing

even when you have a pressure regulator in the system its needed...some regulators have small by pass built in to help with expanison..some may even work for awhile...our water heater rep from bradford white requires expanison tanks in this case...that is why I feel you need one..IMO... fyi we never install new tanks without expanison tanks....best way....

biggles

there are only 5 threaded connections one might be dripping when it heats up....hot/cold...drain...relief.. and the gas valve/temp control how long does t take before water soaks the burner base pan.keep in mind the entire tank is the city pressure heating or not.....can't be condensation from a refill,and for it to be a pin hole it has to flow 24/7 the hot and cold are right into the heater..take a Q-TIP and try to push it into the threaded back part between the opening and the metal cover..of the others to see if it comes out wet..that base pan keeps getting wet it will rust out causing a heater changeout

Curb71

well, checked this morning and the pan is full and the glass under the drain valve is empty.

Curb71

not sure if I understand correctly. the drain pan takes a few hours to fill up. somewhere between 2 and 12 I'd guess. The supply lines at the top of the tank are dry.