Gas and electric heaters fail differently, so it helps to know which type you have before calling. A gas heater has a burner and a flue pipe on top; an electric heater has a power cable and one or two access panels on the side.
If your water heater is leaking
- Turn off power at the breaker (electric) or set the gas control to off or pilot (gas).
- Close the cold-water inlet valve on top of the heater.
- If the leak is heavy, connect a hose to the drain valve and drain the tank to a floor drain or outside. The water may be scalding.
- Keep the area clear and dry, and check that water is not reaching electrical outlets or cords.
If you smell gas near the heater, leave the house and call your gas utility from outside.
What this service solves
- No hot water
- Hot water runs out quickly
- Water too hot or temperature fluctuates
- Popping, rumbling or hissing
- Leaks from valves and fittings
- Pilot or ignition problems
Common symptoms
- No hot water at any fixture
- Lukewarm water or short hot water supply
- Rusty or discolored hot water
- Rotten-egg smell in hot water only
- Rumbling or popping during heating
- Water around the base of the heater
- Relief valve dripping or discharging
Most likely causes
Sediment buildup
Minerals settle at the bottom of the tank, causing rumbling, reduced capacity and overheating of the tank bottom. Common in hard-water areas.
Failed heating element or thermostat (electric)
Electric heaters typically have two elements. One failing usually means lukewarm water or a short supply.
Pilot, thermocouple or ignition failure (gas)
If the pilot will not stay lit or the burner will not ignite, the heater produces no hot water.
Anode rod depletion
The sacrificial anode protects the tank from corrosion. When it is used up, the tank itself starts to corrode.
Broken dip tube
The dip tube sends incoming cold water to the bottom. If it breaks, cold water mixes at the top and hot water runs out quickly.
Excess pressure or temperature
A relief valve that discharges may be doing its job; the cause can be high system pressure or thermal expansion.
How the problem is diagnosed
- Confirm the heater type, age (from the serial number) and capacity.
- Check power at the breaker (electric) or the pilot and gas supply (gas).
- Test elements and thermostats, or the thermocouple and gas control.
- Inspect the relief valve, fittings and tank for leaks.
- Check venting on gas units for proper draft.
Repair and replacement options
| Option | Best for | What to know |
|---|---|---|
| Component repair | Heaters in reasonable condition | Elements, thermostats, thermocouples, igniters, gas controls, dip tubes and valves are replaceable parts. |
| Flushing and descaling | Noise and capacity loss from sediment | Most effective when done regularly; very heavy sediment may not fully clear. |
| Anode replacement | Mid-life tanks | Can extend tank life if done before corrosion sets in. |
| Replacement | Tank leaks or old units | A leak from the tank body means the heater must be replaced. |
What a plumber normally does
- Make the unit safe (power or gas off if needed)
- Diagnose the failed component
- Repair with matching parts
- Restart and test temperature, venting and relief valve
Emergency warning signs
- Tank leaking from the body
- Gas smell near the heater
- Relief valve discharging continuously
- Scorch marks around the burner access or flue
If you see any of these, shut off water first. See emergency plumbing steps.
What affects the cost
We don’t publish national price figures because real quotes vary too much by region, access and the condition of your system. These are the factors that move the price:
- Gas or electric
- Which component failed
- Parts availability for the model
- Venting or code corrections required
- Age of the unit (affects whether repair makes sense)
Ask for a written quote that names the method, materials and any permit or restoration work before work begins.
DIY vs. calling a professional
Reasonable for homeowners
- Resetting an electric heater's high-limit switch (after confirming why it tripped)
- Relighting a pilot following the label instructions
- Flushing a few gallons from the drain valve
- Testing the relief valve per the manufacturer's guidance
Call a professional for
- Gas control, burner and venting work
- Electrical element and thermostat replacement if you are not comfortable working with 240V
- Relief valve or expansion tank issues
- Any leak from the tank
Prevention and maintenance
- Flush the tank periodically, more often with hard water.
- Have the anode rod checked every few years.
- Keep the area around gas heaters clear for combustion air.
- Set temperature around 120°F, which the U.S. Department of Energy suggests for most households.
- Install an expansion tank on closed systems.
Specific water heater repair services
Tankless Water Heater Repair
Owners of tankless (on-demand) units with error codes, cold-water sandwiches or scale problems.
Learn more →Gas Water Heater Repair
Natural gas or propane tank heaters with pilot, burner, control or venting problems.
Learn more →Electric Water Heater Repair
Electric tank heaters with element, thermostat or breaker problems.
Learn more →Water Heater Repair: common questions
Why do I have no hot water?
For electric heaters, check the breaker and the reset button behind the upper panel; a failed element or thermostat is common. For gas heaters, check whether the pilot is lit and the gas valve is on. If the pilot will not stay lit, the thermocouple or gas control may have failed.
Why does my hot water run out so fast?
Common causes are a failed lower element on an electric heater, a broken dip tube, heavy sediment, a thermostat set too low, or a heater that is too small for the household.
Is a leaking water heater an emergency?
A leak from the tank itself is urgent and means the heater needs replacing. Turn off the power or gas and close the cold inlet valve. A drip from the drain valve or a fitting is less urgent but should be checked soon.
Why does my water heater make popping noises?
Popping or rumbling is usually sediment at the bottom of the tank. Water trapped under the sediment boils and bursts through. Flushing may help, and the noise is a sign the tank is working harder than it should.
Why does my hot water smell like rotten eggs?
Bacteria in the tank can react with the anode rod and produce hydrogen sulfide. Replacing the anode with a different alloy and flushing the tank often solves it. If you smell rotten eggs near a gas appliance rather than in the water, treat it as a possible gas leak.
Should I repair or replace an old water heater?
Tank leaks always mean replacement. For other failures, age is the main factor: a relatively young heater with a failed part is usually worth repairing, while a heater near or past the end of its typical lifespan often is not.
How long does a water heater last?
Tank-type heaters commonly last roughly 8 to 12 years, and tankless units often longer, but water quality, maintenance and installation strongly affect lifespan.
Why is my water heater relief valve leaking?
The temperature and pressure relief valve may be faulty, or it may be releasing because pressure or temperature is too high. Thermal expansion in a closed system is a common cause. Do not cap or plug this valve.
Water Heater Repair in specific cities
Local conditions change how this problem shows up. These city guides cover local factors in depth:
- Water Heater Repair in Dallas, TX
- Water Heater Repair in San Antonio, TX
- Water Heater Repair in Miami, FL
- Water Heater Repair in Phoenix, AZ
- Water Heater Repair in Tucson, AZ
- Water Heater Repair in San Diego, CA
- Water Heater Repair in Las Vegas, NV
- Water Heater Repair in Salt Lake City, UT
- Water Heater Repair in Austin, TX
- Water Heater Repair in Fort Worth, TX
- Water Heater Repair in Scottsdale, AZ
- Water Heater Repair in Gilbert, AZ
- Water Heater Repair in Fort Lauderdale, FL
- Water Heater Repair in Glendale, CA
- Water Heater Repair in Anaheim, CA
- Water Heater Repair in Honolulu, HI
- Water Heater Repair in Wichita, KS
- Water Heater Repair in Albuquerque, NM
- Water Heater Repair in Anchorage, AK
- Water Heater Repair in Billings, MT
- Water Heater Repair in Sioux Falls, SD
- Water Heater Repair in Cheyenne, WY
- Water Heater Repair in Colorado Springs, CO
