You’re in the basement looking for something else when you notice it. A little puddle at the base of the water heater. Not huge. But it definitely wasn’t there last week.
A puddle doesn’t automatically mean the tank is done. Sometimes it does, though, so it’s worth ten minutes to figure out which kind you’ve got.
Find the source first
Wipe the floor dry and lay a ring of paper towels around the base. Come back in a few hours. A wet towel on one side, or a drip line running down a pipe, will point you in the right direction.
Look up, not just down. Water that ends up on the floor often started near the top.
The usual suspects
Condensation is the harmless one. A tank full of cold water can sweat after a big draw of hot water, like back-to-back showers. It should stop once the tank heats back up.
The drain valve sits near the bottom. If it isn’t closed all the way, it drips.
Then there’s the temperature and pressure relief valve, on the top or upper side of the tank, with a pipe running down toward the floor. Water coming out of that pipe can mean the valve is opening to let off pressure. Never cap or plug that pipe. It’s a safety device, and it’s there for a reason.
Fittings at the top of the tank can loosen or corrode over time. A brand-new install is worth watching, too. A connection that wasn’t fully tightened can start dripping within a few days.
And then there’s the tank itself. If water is coming out of the body of the tank, it has failed, and it won’t fix itself.
When the floor is the real problem
A slow drip in an unfinished utility room is a plumbing fix. But a lot of water heaters sit in finished basements, right next to carpet and drywall, and water spreads under flooring and wicks up walls well before you see it. Once that happens, the job is drying out the room, not just fixing the heater. You can read about what that work involves at kiserrenovations.com.
Moisture can stay in a wall even after the floor looks dry. And box fans alone won’t solve it. They move air around, but they don’t pull water out of carpet pad or drywall.
What to do right now
If it’s more than a few drops, shut off the cold water going into the heater. That valve is usually on the cold line up top. On a gas heater, turn the control to “pilot” or “off.” On an electric one, flip the breaker.
Then move whatever’s stored nearby. Cardboard boxes and rugs soak water up fast.
What the manufacturer says
Water heater maker A. O. Smith has a technical bulletin on puddles under water heaters, and it lists the same suspects. Condensation, the drain valve and the relief valve are there. So are the piping near the inlet and outlet, the gas valve threads on gas models, the element gaskets on electric models and the tank itself. According to the bulletin, condensation should stop once the tank is above 110 degrees. A dripping relief valve can come from thermal expansion in a closed system, and it suggests comparing your home’s water pressure to the valve’s rating. If the tank itself is leaking, A. O. Smith says to replace the tank.
So, condensation or a loose drain valve? Easy fix. A dripping relief valve deserves a plumber. A leaking tank means a new one. And if the water already made it to the carpet, deal with the drying too, not just the heater.
