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GUIDES
Guides to replacing
a water heater.
Plain guides to types, prices, common problems and what to ask installers.
Costs & quotes
What a replacement really costs, what drives the number and how to tell whether a quote is fair.
Is that water heater quote reasonable?
Start with what is included. Two totals only mean something when they describe the same job.
Water heater replacement cost: what you’ll pay and why
A same-type tank swap usually lands between $1,600 and $2,400 installed. Changing type, fuel or location is what moves the bill, and the cheapest heater to buy is not always the cheapest to own.
What makes one water heater installation cost more than another
The heater is only part of the bill. What drives the rest is how much the job changes your house: the vent, the gas line, the wiring, the location, and code items your old installation never had.
What a water heater costs to run, by type and fuel
At national average prices a standard gas tank costs about $384 a year to run, an electric tank about $919 and a heat pump about $214. Your rates and your hot water use can move those numbers a lot.
Buy the heater yourself, or let the installer supply it?
Compare the whole transaction before a lower equipment price becomes a more complicated job.
Check the incentive date before counting the savings.
A rebate is useful only if your home, equipment and installation qualify.
Does insurance or a home warranty cover a water heater?
Three kinds of coverage can touch a failed water heater, and each pays for a different piece. Here is who pays for what, from the policy and contract language itself.
Choosing a water heater
Tank, tankless or heat pump; gas or electric; what size; which brand. Match the heater to the house.
Tank vs. tankless vs. heat pump water heaters
A tank is the cheapest to install, a heat pump is the cheapest to run, and tankless trades a higher price for hot water that doesn’t run out. Your fuel, your space and your climate decide which trade is worth it.
Tank water heaters: gas, electric, atmospheric and power vent
A tank is the simplest water heater to install and usually the cheapest. The fuel sets how fast it recovers; for gas, the vent sets how hard the job is and what it costs.
Tankless water heaters: honest pros, cons and requirements
A tankless heater never runs out, but only at the flow it can heat. Whether one is worth it depends on your gas line or panel, your water and how your household uses hot water.
Heat pump water heaters: will one work in your home?
A heat pump water heater can cut water heating bills by more than half. Whether one works for you depends on the room it goes in more than on the heater itself.
What size water heater do you need?
Household size gets you in the neighborhood. Your busiest hour of hot water use, and how cold your water arrives, decide the right size.
Gas vs. electric water heater: which is right for your home?
A standard gas tank costs less than half as much to run as a standard electric tank and recovers twice as fast. A heat pump, the electric efficiency option, flips the running-cost math almost everywhere.
Switching from a gas water heater to electric or a heat pump
The heater is the easy part. The switch is decided by your electrical panel, the space around the heater, and what happens to the gas line and the old vent. Here is the order to check them in.
How to read the EnergyGuide label: UEF, FHR, yearly cost
The yellow label is the fastest honest comparison you can make between water heaters, if you know which numbers to trust and which to redo with your own rates.
Hot water recirculation pumps: faster hot water, at what cost
A recirculation pump can put hot water at a far faucet in seconds instead of a minute. Run it on demand and it costs little; run it around the clock and it can more than double the energy you spend heating water.
Problems & warning signs
Leaks, noises, smells, cold showers. What each symptom usually means and when it means replacement.
Repair or replace your water heater?
Where the water is coming from settles most cases. When it doesn’t, the heater’s age, the repair price and the warranty decide, roughly in that order.
How long do water heaters last?
Roughly 8–15 years for a tank, 13–15 for a heat pump model and 15–20 or more for tankless, depending on whose figure you use. Your water and your maintenance decide where in that range yours lands.
How old is my water heater? Reading the serial number by brand
The manufacture date is on the label, usually hidden in the serial number. Each brand hides it differently, and two codes that look alike can mean different things.
Water heater emergency: what to do in the first 10 minutes
Danger to people first, then water, then money. Find your situation below, do the steps in order, and leave anything involving gas lines or wiring to a professional.
Water heater leaking? Find where it’s coming from
Water runs down, so the puddle is rarely where the leak is. Dry everything, find the highest wet spot, and you’ll know within a day whether it’s a cheap part, condensation or a tank on its way out.
No hot water? What to check, step by step
Most no-hot-water calls come down to power, gas, a pilot or a safety shutoff. Here is what you can safely check yourself for each type of heater, in order, and the signs that mean a technician should take over.
Running out of hot water too fast? Here’s why
When the hot water gives out says more than how fast it goes. Match your pattern to the likely cause, run a simple test, then fix it, cheapest option first.
Popping, rumbling, hissing: water heater noises explained
Most water heater sounds are the normal noise of metal, water and flame. A few point to sediment, pressure or a leak, and one combination means the tank is overheating. Here is how to tell them apart, sound by sound.
Rotten-egg smell, rusty or cloudy hot water
One test sorts out most cases: compare the hot tap with the cold. If only the hot water is off, the water heater is the likely source, and the fix depends on the symptom.
Water heater pilot light won’t light or stay lit
A pilot that went out once can usually be relit in a few minutes by following the label on the tank. One that won’t light, or goes out when you let go of the knob, is telling you which part to look at.
Water heater relief valve leaking or dripping
A relief valve that drips is opening because something made it open. When it drips tells you why, and a $10–$20 pressure gauge usually confirms it.
Tankless water heater problems and error codes, by symptom
Every brand numbers its codes differently, but the faults behind them are the same handful. Find your symptom, make the safe checks, and know when to stop.
Installation, codes & safety
Permits, venting, expansion tanks and the parts of an installation that keep your home safe.
The photos that make a better replacement brief.
Show the unit and the space around it. Keep covers closed and stay clear of connections.
Get ready for installation day.
A few questions and a clear path to the heater make the day go more smoothly.
Water heater permits and inspections: what to expect
The model code most US cities use requires a permit to replace a water heater, though some cities exempt a straight swap. Here is who pulls it, what it costs, how the inspection works and why it is worth the trouble.
Water heater code requirements, explained for homeowners
Your city or county decides which code applies, but almost every US code checks the same dozen things. Here is each one, why it exists and what the inspector looks for.
Water heater venting: atmospheric, power vent, direct vent and condensing
A gas water heater’s vent is a safety system first. The type you have decides what a replacement involves, and a furnace upgrade can quietly break it.
Expansion tanks: when you need one and why
Heated water expands. If your plumbing can’t push the extra water back to the street main, pressure climbs every time the heater runs. A small tank on the cold line gives it somewhere to go.
Can you replace a water heater yourself?
Many cities let you replace your own water heater with a homeowner permit. Whether you should depends on the fuel, the warranty and what goes wrong when it’s done badly.
Water heater safety: carbon monoxide, flammable vapors, scalding
A water heater is a tank of scalding water under pressure, often with a gas flame under it. Several safety features keep that boring. Here is what each one does and how to tell when one isn’t working.
Where a water heater can go: garages, attics, closets, relocation
A water heater can go almost anywhere, but every location brings its own requirements. The location also decides much of what the installation costs.
Ownership & maintenance
Make the next heater last: flushing, anode rods, settings and the paperwork worth keeping.
Read the warranty before you compare prices.
Tank, parts and labor coverage are different promises from different companies.
Water heater maintenance: a schedule that actually matters
Most water heaters need about an hour of attention a year. Which hour depends on the type: sediment and the anode rod for tanks, scale for tankless units, a filter and a drain line for heat pumps.
How to flush a tank water heater (and when not to)
Flushing drains the sediment that settles in the bottom of a tank. It’s a reasonable homeowner job if you respect two things: the water can scald, and an electric tank must be completely full before the power goes back on.
Anode rods: what they do and when to check yours
A metal rod inside every tank water heater corrodes on purpose so the steel tank doesn’t. When it’s gone, the tank is next. Here is how to tell, what to replace it with and what the job costs.
Descaling a tankless water heater
A tankless heater has no tank to flush. Instead, a small pump circulates vinegar or descaler through the heat exchanger once a year or more, depending on your water.
What temperature should a water heater be set to?
For most homes the answer is 120°F. A hotter tank is a legitimate choice for some households, but only with a mixing valve between the tank and the taps.
Hard water, softeners and your water heater
Hard water leaves scale on the hottest surfaces in your heater. How much that matters depends on your number, your heater type and what your warranty says.