A water heater usually fails in one of two ways. A part wears out, such as an element, a thermostat or a thermocouple, and the tank is fine. Or the tank itself fails, and no part will save it. The first is a repair. The second is the end of the heater.

Where is the water, and is it from the tank?

Water at the base of the heater is the most important clue, because it changes the question from what to repair to whether to replace.

What you see	Usually	Repair?
Water dripping from a pipe fitting or valve	A loose connection or a failing valve	Often yes
Water from the relief valve discharge pipe	High pressure or temperature, or a worn valve	Depends on the cause
Water pooled under the tank, seam or bottom	The tank has failed	Rarely. Replacement is the usual answer
Rusty water only from hot taps	Corrosion inside the tank	A sign of age, so ask about replacement

If the tank itself is leaking, shut off the cold water supply valve above the heater and the gas or power to the unit, then call. See water heater replacement for what comes next.

Water under your heater? Shut the supply valve and call.

CALL A PLUMBER NOW(727) 766-0323

Gas or electric: which problems are which?

Heater type	Common symptom	Likely cause
Gas	No hot water, pilot out	Thermocouple, pilot assembly or gas control valve
Gas	Slow recovery or lukewarm water	Sediment in the tank or a failing burner
Electric	No hot water at all	A tripped breaker, failed thermostat or upper element
Electric	Hot water that runs out fast	A failed lower element

For a gas heater, do not relight a pilot that keeps going out and do not ignore a gas smell. If you smell gas, leave the house and call the gas utility or 911. Do not try to find the source yourself.

Plumber crouching beside a gas water heater and working at the pipe connections near its base — Looking at the fittings and the base of the tank is how a plumber separates a part that can be repaired from a tank that has failed.

Safe first checks: breaker, gas valve and cold supply

Electric: look at the breaker and the reset button on the heater. Do not open panels or touch wiring.
Gas: confirm the gas valve is open and the pilot is lit. If the pilot will not stay lit, stop.
Either: make sure the cold water supply valve is open and the thermostat has not been turned down.

Stop there. Opening electrical panels or working on gas components is a job for the plumber.

Reading the heater's age: repair or replace?

The serial number on the tank label encodes the manufacture date, and the format differs by brand. Ask the plumber to read it. An older heater with a failed part is a different decision than a newer one with the same part.

Repair makes sense when the tank is sound, the part is inexpensive and the unit is not near the end of its life.
Replacement makes more sense when the tank leaks, repairs keep stacking up or the unit is well past typical age.
Ask for both a repair estimate and a replacement estimate, so you can compare them side by side.

The relief valve and its discharge pipe

The temperature and pressure relief valve is the heater's safety device. If water drips or runs from the discharge pipe, do not cap it or plug it. A valve that discharges is telling you the tank is overheating or the pressure is too high, or that the valve itself is worn.

A valve that drips once after a long hot run may simply be reacting to pressure.
A valve that runs continuously needs a plumber the same day.
A discharge pipe that ends where nobody sees it can leak for a long time. Ask where it ends.

Sediment, noise and slow recovery

A tank that rumbles or pops when it heats has sediment on the bottom that traps water under it. It also slows recovery and works the burner or the lower element harder. Flushing can help, but ask the plumber first on an older tank, since disturbing sediment can open a leak that was sealed by it.

Does a repair need a permit?

A like-for-like part repair usually does not. A replacement or a change to the venting, gas or electrical connection may. The City of Sarasota Building Division's guideline does not name water heaters, so call before assuming either way: 941-263-6494 for the City, 941-861-5000 for Sarasota County Building. Ask your plumber who will confirm and pull any permit.

Beige water heater tank with an instruction label and a valve on a white pipe at its side — The labels on a tank carry the warnings and the rating plate a plumber reads to date the heater.

Location, access and the drain pan

Where the heater sits changes the job. A heater in a closet, an attic or a garage has different access, venting and leak risk. If it sits above living space, ask whether a drain pan with a pipe to a safe spot is in place. A pan that is dry is a quiet reassurance, and one that is wet is early warning.

Tankless units

A tankless unit fails differently. Error codes, scale buildup and lukewarm water at low flow are the common complaints, and descaling can often resolve them. See tankless water heater service for that decision.

How urgent is your heater problem?

Call now: water spreading from the tank, a gas smell, or a relief valve that runs continuously.
Call the same day: no hot water, or a pilot that will not stay lit.
Schedule soon: lukewarm water, noise from the tank, or rust-colored hot water.

For what tends to change the price of a repair or a replacement, see repair and replacement pricing factors.

Water Heater Repair in Sarasota, FL: When It Is Worth Fixing and When It Is Not