A puddle under the water heater is alarming, but not every leak is the tank. Dry the area, then look, and you will usually find the source within a few minutes.
Where to look
The top of the tank. Two pipes enter here, cold in and hot out, with fittings that can loosen or corrode. Water running down the outside of the tank from a fitting at the top is a connection leak, and often a plumber can tighten or replace the fitting without replacing the heater.
The relief valve. On the top or the side, with a lever and a pipe running down toward the floor. If water comes from the end of that pipe, the valve is doing its job: opening because the pressure or temperature in the tank is too high. Occasional drips can happen after heavy use. A steady drip or a regular discharge means either the valve has failed, or the pressure in the house is too high, or the system needs an expansion tank. All three are a plumber's job, and none of them means the tank is finished.
The drain valve. Near the bottom, where a garden hose attaches. Old plastic drain valves weep. A brass cap screwed onto the outlet stops most of them; otherwise the valve can be replaced.
The bottom of the tank. Water coming from underneath the tank, with no other source, means the inner tank has rusted through. There is no repair. The heater must be replaced, and soon, because a rusted tank can go from a drip to a flood without warning.
Condensation. A gas heater that has just refilled with cold water sweats, and the drops fall onto the burner and the floor. It stops once the water warms. If the puddle appears only after heavy use and dries up, that is all it is.
What to do right now
If the tank itself is leaking:
- Turn off the heat: the gas control to Off, or the electric breaker.
- Close the cold water valve on the pipe into the top of the tank.
- If the leak is large, attach a hose to the drain valve and run it to a drain, then open the valve and a hot tap upstairs to let the tank empty.
- Move anything on the floor nearby.
For a connection or valve leak, closing the cold water valve and turning off the heat is enough until a plumber arrives.
Replacing the heater
Tank heaters in Rockland County last around ten years on town water, sometimes less on hard well water. If yours is near that age and the tank is leaking, replacement is the only option. Have the plumber check the water pressure and ask whether an expansion tank is needed, which many towns now require with a new heater. Rockland County requires a permit for a water heater replacement; a licensed plumber handles it.
When to call a plumber
- Any leak from the tank itself
- A relief valve that drips or discharges regularly
- A connection at the top that you cannot stop with gentle tightening
- To fit an expansion tank or a pressure-reducing valve
Find a licensed plumber near your town.