Category: Water Heaters

If you suddenly have no hot water, the cause is usually simple: a tripped breaker or reset button on an electric water heater, or a pilot light that went out or a gas control problem on a gas model. Start by identifying your water heater type, then work through the checks below. If the tank is leaking or you smell gas, stop and get professional help.

Quick answers

• Electric: check the breaker, then the red reset button behind the upper access panel.
• Gas: check that the pilot is lit (older models) or read the status light (newer models).
• Lukewarm water: often a failed lower element (electric) or sediment buildup.
• Running out fast: see Hot Water Runs Out Fast.
• Smell gas: leave the home and call the gas utility from outside.

Step 1: Identify your water heater type

• Gas tank: has a gas pipe and a vent pipe on top. Look for a control knob with ON, OFF and PILOT.
• Electric tank: has a thick electrical cable and two access panels on the side, no vent pipe.
• Tankless: a box on the wall. See the manual for error codes.
• Heat pump water heater: a tall tank with a fan unit on top.

If you have an electric water heater

1. Check the breaker

Electric water heaters use a double-pole breaker, usually 30 amps. If it’s tripped, reset it once. If it trips again, call a technician or electrician: an element or the wiring may be shorted.

2. Press the reset button

With power off at the breaker, remove the upper access panel and insulation. Press the red high-limit reset button firmly. If it clicks, it had tripped. Replace the insulation and cover, then restore power. If it trips again, a thermostat or element may be failing.

3. Test the heating elements

Most electric tanks have two elements. If the upper element fails, you get no hot water. If the lower fails, you get a small amount of lukewarm water.

To test an element: turn the breaker off and confirm with a non-contact voltage tester that no power reaches the terminals. Disconnect one wire from the element and set a multimeter to ohms. A good element usually reads roughly 10 to 30 ohms (for example, about 13 ohms for a 4,500-watt, 240-volt element). A reading of zero or “OL” (open) means the element has failed. Replacing an element requires draining the tank below the element level. If you’re not comfortable working with 240-volt circuits, have a technician do it.

If you have a gas water heater

1. Check the gas supply

Make sure the gas valve on the supply pipe is open (handle parallel to the pipe) and that other gas appliances work.

2. Check the pilot or status light

• Older models: look through the small window at the bottom. If you don’t see a small blue flame, the pilot is out. Relight it following the instructions on the label on the tank.
• Newer models with electronic controls blink a status light. Count the blinks and check the label.

If the pilot won’t stay lit, see Water Heater Pilot Light Won’t Stay Lit.

3. Check the thermostat dial

Someone may have turned the gas control to VACATION or a low setting. The U.S. Department of Energy suggests 120°F as a good setting for most households.

4. Check for a tripped thermal cutoff

Many gas water heaters have a flammable vapor sensor or thermal switch. If it trips, the pilot won’t stay lit until the cause is addressed. This usually requires a technician or part replacement.

If the water is warm but not hot

• Thermostat set too low
• Failed lower element (electric)
• Heavy sediment in the tank reducing capacity (How to Flush a Water Heater)
• Broken dip tube mixing cold water into the hot outlet
• Cold weather increasing demand

If the tank is leaking

Turn off power or gas and the cold water supply valve. See Water Heater Leaking from the Bottom: What to Do Right Now.

When to replace instead of repair

If your tank water heater is more than about 10 years old and needs a major repair, replacement is often the better investment. See How Long Do Water Heaters Last? and Water Heater Replacement Cost.

Frequently asked questions

How long does it take a water heater to reheat?
A typical 40–50 gallon gas tank recovers in about 30–40 minutes; electric tanks often take longer, around 60–80 minutes.

Why do I have hot water in some faucets but not others?
That suggests a faucet or mixing valve problem, not the water heater.

Is it safe to relight a pilot light myself?
Yes, if you follow the instructions on the water heater label exactly and don’t smell gas. If you smell gas, don’t attempt it.

Related guides

• Tankless vs Tank Water Heater
• Water Heater Leaking from the Bottom: What to Do Right Now
• How Long Do Water Heaters Last? Lifespan by Type and Warning Signs

A tank water heater typically lasts about 8 to 12 years, and sometimes up to 15 with good maintenance and soft water. Tankless water heaters often last around 20 years. Hard water, high temperature settings and skipped maintenance shorten lifespan. Because tank failures can cause water damage, it’s smart to plan a replacement once your tank passes 10 years.

Quick answers

• Gas tank: about 8–12 years. Electric tank: about 10–15 years.
• Tankless: about 20 years. Heat pump water heater: about 10–15 years.
• Find the age in the serial number on the label.
• Rusty water, leaks at the base and rumbling noises are warning signs.
• Yearly flushing and anode rod checks help a tank last longer.

Lifespan by type

Type	Typical lifespan	Main reason it fails
Gas tank	8–12 years	Tank corrosion
Electric tank	10–15 years	Tank corrosion, element failures
Tankless (gas or electric)	~20 years	Heat exchanger scale, components
Heat pump (hybrid)	10–15 years	Tank corrosion, compressor/fan

How to find your water heater’s age

Look at the manufacturer’s label on the side of the tank. The manufacture date is often encoded in the serial number. Common formats use a letter for the month and two digits for the year, or the first four digits for year and week. Search for your brand plus “serial number date code” to decode it.

Signs your water heater is failing

• Water leaking from the tank body (not from a valve): replace soon. See Water Heater Leaking from the Bottom.
• Rusty or discolored hot water (but cold is clear): the tank may be corroding.
• Rumbling, popping or banging: heavy sediment. See Water Heater Making Popping Noise.
• Less hot water than before or water that cools quickly.
• Moisture or rust around the base.
• Frequent repairs, especially on an older unit.

How to make a water heater last longer

1. Flush yearly to remove sediment (how to flush).
2. Check the anode rod every 2 to 3 years and replace it when it’s heavily corroded. The anode rod corrodes so your tank doesn’t.
3. Set the temperature to about 120°F. Higher settings speed corrosion and scaling and increase scald risk.
4. Install an expansion tank if your home has a closed plumbing system (common with backflow preventers). It reduces pressure stress.
5. Test the T&P relief valve as recommended by the manufacturer.
6. Soften very hard water, or at least flush more often.

Repair or replace?

Situation	Usually
Under 6 years, valve or element problem	Repair
6–10 years, thermostat, element, thermocouple	Repair
Over 10 years, any significant repair	Consider replacing
Leak from the tank body at any age	Replace

Costs: Water Heater Replacement Cost (Tank and Tankless).

Replace before it fails

A failing tank can release dozens of gallons of water. If your heater is in an attic, finished basement or interior closet, replacing it proactively around year 10 to 12 can prevent costly water damage. Install a drain pan and a leak alarm under the new heater.

Frequently asked questions

Can a water heater last 20 years?
Tankless units often do. Tank heaters rarely do unless they have soft water, regular maintenance and anode replacements.

Does a water heater warranty indicate its lifespan?
Somewhat. Tank warranties are commonly 6, 9 or 12 years, reflecting differences in anode rods and construction.

Should I replace with the same type?
Not necessarily. Compare options: Tankless vs Tank vs Heat Pump.

Related guides

• No Hot Water? How to Troubleshoot
• Water Heater Leaking from the Bottom: What to Do Right Now
• Tankless vs Tank vs Heat Pump Water Heaters: Real Costs Over 10 Years

A water heater leaking from the bottom is usually caused by a loose or faulty drain valve, water from the temperature and pressure (T&P) relief valve, condensation, or a corroded tank. The first three can often be fixed for under 50 USD. If the tank itself is leaking, it can’t be repaired and the water heater needs to be replaced. Start by shutting off the power or gas and the cold water supply.

Quick answers

• Electric: turn off the breaker. Gas: set the gas control to OFF.
• Close the cold water valve at the top of the heater.
• Dry the area and look for the source: drain valve, relief valve pipe, fittings or tank.
• Water coming from the tank body itself means replacement.
• Tank water heaters commonly last about 8 to 12 years.

Step 1: Make it safe

1. Cut the energy. Electric: switch off the water heater’s breaker. Gas: turn the gas control knob to OFF. Never let an electric heater run with a partly empty tank: the elements can burn out in seconds.
2. Stop new water. Close the cold water supply valve on the pipe going into the top of the tank.
3. Protect the floor. Place towels or a pan under the heater. If water is spreading toward outlets or electrical equipment, keep away and call a professional.
4. Be careful with hot water. Tank water can be hot enough to scald. Let it cool before touching valves.

Step 2: Find where the water comes from

What you see	Likely cause	Fix	Typical cost
Drip from the drain valve near the bottom	Valve not fully closed or worn washer	Tighten it, cap it, or replace the valve	10–40 USD (DIY)
Water at the end of the pipe running down the side	T&P relief valve opening	Check water pressure and temperature; replace valve if it keeps dripping	20–60 USD (DIY) or 150–300 USD (plumber)
Small drops on the outside after filling	Condensation	Usually stops once water heats up	0 USD
Water pooling from under the jacket or base	Corroded, cracked tank	Replace the water heater	See replacement cost
Wet fittings at the top that drip down	Loose inlet or outlet connection	Tighten or replace the fitting	10–30 USD (DIY)

Important: never cap, plug or remove the T&P relief valve. It protects the tank from dangerous pressure and temperature.

Step 3: Repair or replace?

Repair makes sense when the leak comes from a valve or fitting and the heater is under about 8 years old. Replace it when the tank body is leaking, the heater is 10 or more years old, or you see rusty hot water.

How to check your heater’s age: look at the serial number on the label. Most brands encode the year and month of manufacture in the first characters. Search the brand name with “serial number date code” to decode it.

A real-world example

A homeowner finds a puddle under a 9-year-old 50-gallon gas heater. The drain valve is dry and there’s no water at the end of the relief valve pipe. Looking under the burner access panel, water is dripping from the base of the tank: internal corrosion. The right move is to shut off gas and water, drain the tank to prevent more water damage, and schedule a replacement. Waiting risks a full tank of water on the floor.

How to drain the tank if the body is leaking

1. Keep the power or gas off and the cold water valve closed.
2. Connect a garden hose to the drain valve and run it to a floor drain or outside.
3. Open a hot water faucet in the house to let air in.
4. Open the drain valve and let the tank empty. Expect sediment at the end.

Detailed guide: How to Flush a Water Heater (Step by Step).

Common mistakes

1. Turning the power back on before the tank is full again (burns electric elements).
2. Ignoring a small leak: tank leaks get worse, not better.
3. Overtightening a plastic drain valve and cracking it.
4. Plugging the relief valve to stop a drip.
5. Paying for repairs on a 12-year-old heater instead of planning a replacement.

Frequently asked questions

Is a leaking water heater an emergency?
If water comes from the tank body or near electricity, treat it as urgent. A valve drip should be fixed within days.

Can I still use hot water?
Not if the tank is leaking. Shut it down and plan the replacement.

Does homeowners insurance cover it?
Sudden water damage is often covered, but the water heater itself usually isn’t. Check your policy.

Why is my relief valve dripping?
The tank pressure or temperature is too high, the valve is worn, or your home needs a thermal expansion tank. A plumber can test water pressure.

Related guides

• Water Heater Replacement Cost (Tank and Tankless)
• Tankless vs Tank Water Heater
• How Long Do Water Heaters Last?

Gas and electrical work can be dangerous. If you’re unsure, contact a licensed plumber.

A standard tank water heater is the cheapest to buy, a tankless model lasts longer and never runs out of hot water at its rated flow, and a heat pump water heater usually has the lowest operating cost if you currently heat water with electricity. For most households replacing a working gas tank, another gas tank or a tankless unit makes sense. For households with electric water heating, a heat pump water heater is often the best long-term value.

Quick answers

• Tank: lowest upfront cost, about 8–12 years of life, limited hot water supply.
• Gas tankless: endless hot water at its flow rate, often 20 years of life, higher install cost.
• Heat pump water heater: uses roughly a third to half the electricity of a standard electric tank.
• Switching from tank to gas tankless may require new gas lines and venting.
• Choose based on fuel available, household size and how long you’ll stay in the home.

Side-by-side comparison

Factor	Gas tank	Electric tank	Gas tankless	Heat pump (hybrid electric)
Typical installed price	Low	Lowest	High	Medium to high
Operating cost	Medium	Highest	Lower than gas tank	Lowest of electric options
Typical lifespan	8–12 years	10–15 years	~20 years	10–15 years
Hot water supply	Limited by tank size	Limited by tank size	Unlimited at rated flow	Limited by tank size; slower recovery
Space	Large	Large	Small, wall-mounted	Large, needs surrounding air space
Maintenance	Flush yearly	Flush yearly	Descale yearly in hard water	Clean air filter, flush yearly

Operating cost: how they compare

The DOE’s Uniform Energy Factor (UEF) on the yellow EnergyGuide label lets you compare efficiency directly. Higher UEF means lower operating cost:

• Standard gas tank: UEF often around 0.6–0.7
• Gas tankless: around 0.8–0.95
• Standard electric tank: around 0.9–0.95
• Heat pump water heater: often 3.0–4.0 or more

An electric heat pump water heater with a UEF of 3.5 uses roughly a quarter to a third of the electricity of a standard electric tank for the same hot water. The EnergyGuide label also shows estimated yearly operating cost.

10-year cost example

These are illustrative numbers for a family of four. Your costs will differ by prices and usage.

Type	Installed price (example)	Yearly energy cost (example)	10-year total
Gas tank, 50 gal	2,000 USD	350 USD	~5,500 USD
Gas tankless	4,000 USD	270 USD	~6,700 USD
Electric tank, 50 gal	1,600 USD	650 USD	~8,100 USD
Heat pump, 50 gal	3,500 USD	220 USD	~5,700 USD

The tankless unit can come out ahead if it lasts 20 years and avoids a second tank replacement. The heat pump wins against a standard electric tank in most scenarios.

Tankless: pros and cons

Pros: endless hot water at its rated flow rate, small footprint, long life, no standby heat loss.

Cons: higher installation cost, may need a larger gas line and new venting, a short delay before hot water arrives, and limited flow if several showers run at once. Hard water requires regular descaling.

Heat pump water heaters: pros and cons

Pros: very low operating cost, dehumidifies and cools the space it’s in (a plus in garages and basements in warm climates).

Cons: taller and needs space for airflow (often around 700 cubic feet or ventilation), slower recovery in “heat pump only” mode, a fan noise similar to a dehumidifier, and less efficient in cold spaces.

Which should you choose?

Your situation	Good choice
Gas available, tight budget	Gas tank
Gas available, staying 10+ years, high demand	Gas tankless
Electric only	Heat pump water heater
Small home, low usage, limited space	Small tank or point-of-use tankless
Large family, multiple simultaneous showers	Large tank or properly sized tankless

Size it correctly first: What Size Water Heater Do I Need?

Frequently asked questions

Do tankless water heaters really save money?
They save on energy, but higher installation cost lengthens the payback. They make the most sense when they’re expected to last 20 years.

Can a heat pump water heater go in a closet?
Only if the closet has enough air volume or ventilation as specified by the manufacturer.

Is the federal tax credit still available?
The federal 25C credit ended for installations after December 31, 2025. See Heat Pump Tax Credit 2026.

Related guides

• Water Heater Replacement Cost (Tank and Tankless)
• How Long Do Water Heaters Last?
• Water Heater Leaking from the Bottom: What to Do Right Now