What should I do if my water heater is leaking

Key points

A puddle does not prove the tank has failed; connections, valves, relief discharge, and condensation can wet the same floor area.

A relief pipe that is dripping or discharging must stay open and needs to be checked.

Report whether the heater is gas, electric, heat-pump, or tankless and where water first becomes visible.

First, stay clear of hot water and wet controls

Keep away from hot water
Do not touch the puddle or discharge pipe to judge temperature. CPSC describes tap-water scalding as a burn hazard, so treat water from the heater as potentially hot. ^[4]
Stop using hot water
Do not run showers, hot-water faucets, the dishwasher, or the washing machine on hot. Using hot water causes new cold water to enter a storage heater.
Close the cold inlet only if it is safe
Use only the clearly identified cold-water valve serving the heater. If the valve or the floor around it is wet, hot, damaged, or hard to reach, leave it alone and tell the plumber that the water is still on.
Leave wet controls alone
Do not remove an electrical access panel or touch wet wiring. CDC says wet electrical equipment should be inspected before returning to service. If water reached a gas burner or gas control, do not relight or operate it; A. O. Smith directs qualified evaluation or replacement of a flooded heater and says not to light an automatic burner by hand. ^[3] ^[2]

A safe visual check can identify the starting area, but water running down the jacket can make the apparent source misleading.
Where water first appears	What may be involved
Top piping or flexible connectors	Cold inlet, hot outlet, shutoff, union, or nearby piping
Relief valve or discharge pipe	Relief activation, valve connection, pressure, temperature, or thermal expansion
Drain valve	Loose closure, worn valve, or threaded connection
Bottom seam or tank jacket	Water tracking from above, condensation, or tank leakage

Fuel or energy type and whether the unit has a storage tank.
Brand, model, and any display message visible without opening a cover.
Exact first wet point: top fitting, relief pipe, drain valve, jacket, seam, or adjacent pipe.
Whether leakage is steady, occurs only while heating, or began after heavy hot-water use.
A. O. Smith lists condensation, piping, drain-valve leakage, relief discharge, gasket leakage, and tank leakage as distinct puddle sources. ^[1]

A supply connection, accessible shutoff, drain valve, or replaceable relief-valve connection may be repairable.

Water coming through the tank jacket or from a confirmed tank seam points to a failed storage tank.

The repair still needs to address why the connection or safety device leaked.

Patching the outer jacket does not repair the pressure tank inside it.

The heater can be refilled and checked after the repair by following the manufacturer’s procedure.

Replacement planning must account for capacity, energy source, venting or electrical needs, drainage, and access.