Water Heaters
Replacement, repair and running costs for tank, tankless and heat pump water heaters, plus how to read the serial number and judge a quote.
A tank water heater is one of the few appliances almost every US home has, and it fails on a schedule: most tanks leak somewhere between year 8 and year 12. That makes it the most common emergency purchase homeowners face, and emergencies are where quotes get expensive. This section exists so you know the numbers before the tank does.
If what goes into the tank is part of your problem, our water treatment section covers softeners and reverse osmosis, including how to find out whether your water is hard before anyone quotes you for it.
Tools for this topic
Water Heater Age Decoder
Find out how old your water heater is from its serial number. Covers Rheem, Ruud, A.O. Smith, State, Bradford White, Kenmore, GE and related brands.
Open tool →Water Heater Replacement Cost Calculator
Free water heater replacement cost calculator with every line item and its source. Tank, tankless and heat pump, by size, with a quote check.
Open tool →Questions answered
- How much does it cost to replace a 30-gallon water heater?Updated 2026-09-22Replacing a 30-gallon tank water heater costs $550 to $2,100 installed according to Fixr (January 2026), and $700 to $2,100 if it is a gas unit. A 30-gallon tank suits one or two people. The important number is the comparison: a 40-gallon tank costs $550 to $2,300, so going one size down saves almost nothing on the purchase and gives up a third of the capacity.
- How much does it cost to replace a 40-gallon water heater?Updated 2026-09-22Replacing a 40-gallon tank water heater costs $600 to $2,300 installed. Fixr (January 2026) puts it at $700 to $2,300 with an average of $1,650; This Old House (June 2026) puts it at $600 to $1,200. The gap is not a disagreement about the same job: the low figure is a bare like-for-like electric swap, the high figure includes gas venting, code items and premium units.
- How much does it cost to replace a 50-gallon water heater?Updated 2026-10-30Fixr's 50-gallon guide (updated January 26, 2026) puts installation at $900 to $2,500 with an average of $1,800 for a standard natural gas unit. This Old House's water heater guide (updated June 17, 2026) puts the same 50-gallon tank at $700 to $1,800, using cost estimates it credits to The Home Depot. The two overlap in the middle and disagree at both ends, which is mostly a question of who was asked: a retailer that sells the tanks, or a pricing database built from contractor jobs.
- How much does it cost to replace a 75-gallon water heater?Updated 2026-09-22Replacing a 75-gallon tank water heater costs $900 to $3,500 installed. Fixr (January 2026) puts it at $1,500 to $3,400 with an average of $2,100; This Old House (June 2026) puts it at $900 to $2,300. At this size the fuel choice splits the price: a 75-gallon electric tank runs $1,000 to $2,000 installed, a gas one $1,300 to $3,500.
- How much does it cost to replace an 80-gallon water heater?Updated 2026-09-22Replacing an 80-gallon tank water heater costs $1,000 to $4,000 installed. This Old House (June 2026) puts it at $1,000 to $3,000; Fixr (January 2026) puts it at $1,200 to $3,600 for all fuels and $1,300 to $4,000 for gas. Two costs are specific to this size: floor reinforcement at $300 to $800, and the fact that 80 gallons is the standard size for heat pump tanks, which changes the whole calculation.
- How old is my American water heater?Updated 2026-10-09On an American water heater the first two digits of the serial number are the year and the next two the production week. InspectApedia's photographed example is serial 9950123040, which decodes to 1999, week 50, and they give a second: 9201 reads as the first week of 1992. Two other formats exist, one with a leading letter and one using a month letter instead of a week. InspectApedia also states outright that none of these work on older American Appliance Mfg. Corp. units, and gives a method for those instead of a guess.
- What does it cost to replace a water heater anode rod?Updated 2026-09-22Replacing the anode rod in a tank water heater costs $125 to $300 fitted, according to Fixr (August 2025). This Old House (May 2026) says to inspect it every three to five years and replace it when more than 6 inches of the core wire is showing or the rod is under half an inch thick. Against $900 to $3,000 for a new water heater, it is the cheapest maintenance item on the appliance and the one that decides how long the tank lasts.
- How old is my A.O. Smith water heater?Updated 2026-10-08On a current A.O. Smith water heater the first four digits of the serial number are the date: the first two are the year, the next two are the production week. InspectApedia gives the example 1604 123456, which decodes to week 4 of 2016, and notes that this format has been in use since 2008. Older plates use four other formats, including two that start with a letter for the month. The order matters more than anything else here, because Rheem uses the opposite order and reading an A.O. Smith plate by the Rheem rule can put the date out by years.
- Should you install a water heater yourself?Updated 2026-09-23Doing it yourself saves the labor, which is $300 to $1,500 on a tank job per Fixr (January 2026) or $300 to $800 per This Old House (June 2026). Both sources recommend against it. The strongest reasons are not the obvious ones: most manufacturers void the warranty, insurance may not cover water damage from a unit that was not professionally installed, and many jurisdictions require a licensed plumber to meet code.
- Electric or gas tankless water heater: which should you buy?Updated 2026-09-23An electric tankless water heater costs $650 to $2,500 installed and a natural gas one $1,650 to $3,500, according to This Old House (June 2026). Electric is cheaper to buy and about twice as expensive to run. The deciding factor is usually neither: an electric whole-house unit needs 120 to 160 amps of dedicated service, which most houses do not have.
- What does an emergency water heater replacement cost?Updated 2026-09-22After-hours or weekend water heater installation costs $200 to $500 more than a planned one, and water damage repair from a failed unit runs $500 to $2,500, according to This Old House (June 2026). A planned replacement averages $1,400 to $1,950. The premium is real labor and real damage, not a markup, which is why both sources recommend replacing a tank past 10 years before it fails.
- Gas or electric water heater: which is cheaper?Updated 2026-09-22An electric water heater costs less to install, at $800 to $1,500 against $1,000 to $2,700 for gas (Fixr, January 2026). It costs about twice as much to run, at roughly $720 a year against $300 to $450 for a comparable gas unit. Over a 10-year life the running-cost gap is $2,500 to $4,000, which is several times the purchase price difference. On published figures gas wins on cost wherever a gas line already exists.
- How old is my GE water heater?Updated 2026-10-09GE water heaters use four documented serial formats, and the trap is that two of them read the first digits differently. InspectApedia's GE page lists GE MMYY, GE A WWYY, GENG MMYY and GERN MMYY, and its moderator calls WWYY, week number then year, the common encoding. Their worked example is confirmed by the plate itself: serial GE A511315388 reads week 51 of 2013, and the enlarged data tag states a manufacture date of 18 December 2013. So read the format first and the digits second.
- How much does a heat pump water heater cost?Updated 2026-09-22A heat pump water heater costs $2,750 to $3,500 installed according to This Old House (May 2026), with Fixr's installation guide (January 27, 2026) putting the range at $1,200 to $4,600 across sizes and its 75-gallon guide (January 22, 2026) at $2,800 to $5,800. It runs on about a third of the electricity of a standard electric tank. Energy Star figures put a 40-gallon hybrid at $104 a year against $400 for a 40-gallon electric tank, and a 30% federal tax credit of up to $2,000 applies to certified units.
- How long does a water heater last?Updated 2026-09-22A tank water heater lasts 8 to 12 years and a tankless unit 15 to 20, on the figures both Fixr and This Old House publish most often. The same sources also publish 10 to 15 years for tanks elsewhere on their own sites. The difference is what is being measured: 8 to 12 is when units typically start failing, 10 to 15 is what a maintained unit reaches. Which one you get depends mostly on the anode rod and the water.
- How long does a water heater installation take?Updated 2026-09-23A like-for-like tank replacement takes 1 to 3 hours according to This Old House (June 2026) and 2 to 4 hours according to Fixr (January 2026). A tankless installation takes 4 to 8 hours. After the job, a gas tank needs 30 to 40 minutes to heat up and an electric one up to 60, so plan on no hot water for most of a working day either way.
- How old is my Kenmore water heater?Updated 2026-10-09Sears never built water heaters, and a Kenmore plate decodes by the A.O. Smith family rule: the first two digits are the year and the next two the production week. Both of our references place Kenmore on that side of the industry, and InspectApedia's State page lists Kenmore and Sears among the badges State Industries produced. The model number tells you nothing, because every Kenmore water heater model begins with 153, which is Sears' category code for the product group rather than a code for the factory. Kenmore water heaters were discontinued around 2018.
- No hot water? What each possible fix costsUpdated 2026-09-22On an electric water heater the usual causes are a tripped breaker or blown fuse at $50 to $225, a thermostat at $75 to $250, or a heating element at $200 to $750. On a gas unit it is normally the pilot light or thermocouple, at $75 to $325. All figures from Fixr (August 2025). Work through them in that order, because the cheap causes are also the common ones.
- How much does a propane water heater cost?Updated 2026-09-23A propane tank water heater costs $700 to $2,500 installed according to Fixr (January 2026), and a propane tankless unit $1,400 to $3,500 per This Old House (June 2026). The appliance is essentially a natural gas unit, so the purchase price is similar. What differs is the running cost, about $350 a year for tankless against about $250 for natural gas, and the fuel tank itself, which neither source includes.
- Should you repair or replace a water heater?Updated 2026-09-22Repair if the unit has at least half its expected life left and the repair costs less than half of replacement, which is Fixr's published rule (January 2026); This Old House (June 2026) says replace when repair exceeds half the replacement cost or the unit is 10 or more years old. In practice the decision is made by the part that failed: a valve, thermostat or pilot light at $75 to $175 is always worth fixing, and a corroded tank at $600 to $2,000 almost never is.
- Rheem or A.O. Smith: what actually differs?Updated 2026-10-10Rheem and A.O. Smith are the two groups behind most water heaters sold in the United States, and the practical difference for an owner is which badges each one stands behind and how each one codes a date. Rheem builds for Ruud, Richmond, GE, Hotpoint and Lowe's own brand. A.O. Smith builds for State, American, Reliance, U.S. Craftmaster, Whirlpool and Kenmore, having bought GSW and American Water Heater Company by 2006. Their serial numbers run in opposite orders, which is the single most common source of a wrong age.
- How old is my Rheem water heater?Updated 2026-10-08On a Rheem water heater the first four digits of the serial number are the month and then the year, the reverse of A.O. Smith. InspectApedia's example RN 1292A29282 decodes to December 1992, and Fast Water Heater's example 0720 F12345 decodes to July 2020. Strip any letter prefix such as R, RN or RHNG before you count. InspectApedia documents nine different Rheem formats across the eras, and notes that Rheem's own online checker does not work on older serial numbers.
- How old is my Rinnai water heater?Updated 2026-10-09Rinnai changed its serial format, and our two references each document a different era. InspectApedia gives the digit form, YYMM followed by eight digits, so the first two digits are the year and the next two the month. Fast Water Heater describes units from 2009 onward starting with two letters instead, the first for the year and the second for the month, with the year run skipping the letter I. That skip is the trap: counting straight through the alphabet puts every unit from 2017 onward a year out.
- How much does a solar water heater cost?Updated 2026-09-22This Old House (June 2026) puts a solar water heater at $2,000 to $5,500 installed. Fixr's dedicated solar guide (January 2025) puts it at $8,000 to $10,000 with an average of $9,000. Both are right about different systems: the low figure is a passive system that heats about 40% of a household's water and needs a backup, the high one is a full active indirect system with a 100-gallon tank.
- How old is my State water heater?Updated 2026-10-08State is the one brand in this family where the published references disagree. InspectApedia's State page says State Industries encode the age in the first three positions as a month letter plus a two-digit year, so a serial starting A00 is January 2000, with a four-digit variant where 0910 is September 2010. Fast Water Heater instead groups State with A.O. Smith and reads the first four digits as year then week. The test is simple: if your serial starts with a letter, use the month-letter rule, and if it starts with four digits, you have to settle which of the two applies.
- What does it cost to switch from a tank to a tankless water heater?Updated 2026-09-22A tankless water heater costs $1,200 to $3,500 installed according to This Old House (June 2026) and $2,500 to $4,500 according to Fixr (January 2025). Switching from an existing tank adds work a straight tankless replacement does not need: a larger gas line at $350 to $800, venting at $400 to $800, and on electric units a panel or circuit upgrade at $200 to $2,000. That surcharge, not the unit price, is what decides whether the switch is worth it.
- How much does tankless water heater repair cost?Updated 2026-09-22Tankless water heater repairs cost $100 to $650, with electric units at $100 to $600 and gas at $150 to $650, according to Fixr (August 2025). That is the lowest repair range of any water heater type, because there is no tank to crack or corrode. The recurring cost is annual descaling at $100 to $500 per This Old House (June 2026), and it is not optional in hard water.
- Does where you live change what a water heater costs?Updated 2026-09-23Yes, and by more than most line items on the job. This Old House (June 2026) puts Pacific Northwest prices at up to 45% above the national average of $1,950, the Gulf Coast at 10% to 20% above, the Mid-Atlantic and Midwest at 5% to 10% below, and South Florida at 20% below. The drivers are local labor rates, building codes and permit fees.
- How much does a water heater dip tube replacement cost?Updated 2026-09-25Replacing a dip tube costs $100 to $250 with labor included, per Fixr's water heater repair guide (August 29, 2025). The dip tube directs incoming cold water to the bottom of the tank so it does not mix with the hot water at the top, and Fixr's description of the failure is exactly the complaint people bring: when dip tubes break, the hot water runs out very quickly. The same guide names a faulty thermostat as the other cause of that symptom, priced at $100 to $250 to replace.
- What do water heater efficiency ratings mean?Updated 2026-09-23Uniform Energy Factor (UEF) is how much of the energy a water heater consumes ends up in the hot water. A conventional tank runs at 58% to 60% and a tankless unit at 92% to 95%, per This Old House (June 2026). A heat pump rates above 3.0 because it moves heat rather than making it, and Fixr (January 2026) reports an Energy Star electric unit at EF 3.30 or higher saves about $600 a year.
- Do you need a water heater expansion tank, and what does it cost?Updated 2026-09-22An expansion tank costs $40 to $150 installed according to This Old House (June 2026) and $150 to $400 according to Fixr (January 2026). You need one if your home has a pressure-reducing valve or a check valve on the main water line, which makes the plumbing a closed system. Without it, heated water has nowhere to expand and the pressure pushes out through the relief valve.
- How much does a water heater gas valve replacement cost?Updated 2026-09-25Replacing a gas valve on a water heater costs $150 to $300 with labor included, per Fixr's water heater repair guide (August 29, 2025), which also notes that gas valve and control valve are the same part under two names. It is the piece that decides whether gas reaches the burner at all, so a unit whose pilot stays lit but whose burner never fires usually points here. The cheaper suspect below it is the thermocouple at $150 to $325, the cheapest is a pilot light repair at $75 to $175.
- How much does a water heater heating element replacement cost?Updated 2026-09-25Replacing a heating element costs $200 to $750 with labor included, per Fixr's water heater repair guide (August 29, 2025), which makes it the most expensive routine part on an electric tank short of the tank itself at $600 to $2,000. Elements rarely die of old age alone. This Old House's flushing guide describes sediment collecting at the bottom of the tank, where the heating element sits, and calcifying into a layer that traps heat and overworks the lower element.
- How much does a plumber charge to install a water heater?Updated 2026-09-22Labor for a tank water heater replacement runs $300 to $1,500, which Fixr's installation guide (January 27, 2026) puts at 18% to 50% of the total job. Its size-specific guides quote lower floors for a straightforward swap, $140 for a 40-gallon unit. Plumbers charge $40 to $200 an hour according to This Old House (June 2026), and a standard swap takes 1 to 3 hours. Those two figures do not multiply out to the quoted labor ranges, and the gap is the single most useful thing to understand before reading a quote.
- Why is your water heater leaking, and what does the fix cost?Updated 2026-09-22Water pooling under a water heater comes from one of four places, and the cost depends entirely on which. A leaking relief valve is $100 to $250 to replace, a drain valve $100 to $200, a loose fitting can be as little as $50, and a corroded tank cannot be repaired at all. Figures from Fixr (August 2025); the diagnosis follows This Old House (May 2026).
- What does a water heater really cost over its whole life?Updated 2026-09-23Over a 20-year horizon, a standard electric tank costs roughly $19,100 and a heat pump water heater roughly $12,500, once you count purchase, replacement, running cost and maintenance. A gas tankless unit is the lowest at about $11,100. The cheapest unit to buy is rarely the cheapest to own, because running cost is three to ten times the purchase price over the life of the appliance.
- What does water heater maintenance cost?Updated 2026-09-22A tank flush costs $100 to $250 and an annual maintenance plan $100 to $300 a year, per This Old House (June 2026). An anode rod replacement, the item that actually decides how long the tank lasts, is $125 to $300 per Fixr (August 2025). A tankless unit needs descaling at $100 to $500 a year instead. Set against a $900 to $3,000 replacement, all of it is cheap.
- How much does it cost to fix a noisy water heater?Updated 2026-09-25Fixing a water heater that is making strange sounds costs $150 to $600, per Fixr's water heater repair guide (August 29, 2025), and the same guide says the price depends on the type of sound: rumbling comes from sediment or mineral buildups, hissing indicates leaks. The cheap end is a flush, which Fixr prices as a professional service at $100 to $250. This Old House's maintenance guide agrees on the cause, noting that rumbling or popping sounds often signal sediment buildup in the tank, and that flushing should resolve it.
- Do you need a permit to replace a water heater, and what does it cost?Updated 2026-09-22Most local building departments require a permit to replace a water heater. A simple like-for-like swap costs $25 to $300 according to Fixr (January 2026) and $50 to $200 according to This Old House (June 2026). The $1,500 top end that Fixr publishes applies to jobs that add a new gas line or make major plumbing changes, not to a straight replacement.
- What does it cost to fix a water heater pilot light?Updated 2026-09-25Fixr's water heater repair guide (August 29, 2025) prices a pilot light repair at $75 to $175 and a pilot light replacement at $75 to $150, labor included, which makes it one of the cheapest things that can go wrong on a gas unit. It is also the one where the answer may cost nothing, because a pilot that has simply blown out can be relit. This Old House names an unlit pilot as the first thing to check when there is no hot water, and calls it a relatively easy fix.
- How much does a water heater pressure relief valve cost to replace?Updated 2026-09-25Getting the pressure relief valve replaced costs around $100 to $250 with labor included, per Fixr's water heater repair guide (August 29, 2025), and repairing a valve rather than replacing it runs $75 to $150. It is the cheapest part on the tank measured against what it prevents. This Old House's plumbing expert Richard Trethewey puts it plainly: if the thermostat fails and just keeps calling for heat, the temperature and pressure relief valve is the one more very important safety device standing between that and a tank that explodes.
- What rebates and tax credits can you claim on a water heater?Updated 2026-09-23A heat pump water heater can carry a 30% federal tax credit of up to $2,000, and a gas tankless unit rated 0.95 EF or higher up to $600, according to This Old House (May and June 2026). Utility rebates run $100 to $2,500 and manufacturer rebates $100 to $400. A standard gas or electric tank generally qualifies for none of it.
- What does it cost to move a water heater to a new location?Updated 2026-09-22No current cost guide publishes a single price for relocating a water heater. Built from the line items This Old House (June 2026) and Fixr (January 2026) do publish, a move within the same floor adds roughly $700 to $3,000 on top of the replacement itself, and a move into an attic or a tight closet adds more. We are not going to quote a figure neither source states.
- How much does water heater repair cost?Updated 2026-09-25Water heater repair costs $150 to $750 with an average of $450, per Fixr's water heater repair guide (August 29, 2025). The same guide puts electric units at $100 to $650 and gas units at $150 to $750, and prices the cheapest fix, a blown fuse, at $50 to $75 against the most expensive, a new tank, at $600 to $2,000. That last figure is the one that decides the question, because a whole new unit starts near it.
- What does it cost to run a water heater each month?Updated 2026-09-23Water heating is about 18% of a household's utility cost, which works out to $47.88 a month or $574.56 a year on an average US utility bill, according to the Department of Energy as cited by Fixr (January 2026). By fuel, a 50-gallon tank runs $50 to $63 a month on electricity, $27 to $40 on gas, $19 to $29 on a heat pump and $8 to $21 on solar.
- What does it cost to fix a water heater that smells like rotten eggs?Updated 2026-09-25If your water heater smells bad, Fixr's water heater repair guide (August 29, 2025) puts the fix at $200 to $600, and names the cause: hydrogen sulfide, which produces a rotten egg smell around the tank and is usually caused by bacteria or corrosion in the system. The same guide says the tank may need flushing and a new anode rod, which it prices at $125 to $300. Before any of that, settle one question. This Old House's safety guide lists a rotten egg smell as a possible sign of a gas leak, and there the instruction is to evacuate and call the gas company, not to book a plumber.
- What temperature should a water heater be set to?Updated 2026-10-10This Old House's maintenance guide says to set the dial to 120 degrees Fahrenheit, and quantifies the saving: for every 10 degrees you lower the temperature, you can expect to save up to 5 percent in energy costs. Its safety guide reports a different figure, that OSHA recommends a maximum of 140 degrees Fahrenheit to prevent scalding while still being hot enough to kill bacteria. The two numbers answer different questions, and which one is right for you depends on who lives in the house.
- How much does a water heater thermocouple replacement cost?Updated 2026-09-25Replacing a thermocouple costs $150 to $325 with labor included, per Fixr's water heater repair guide (August 29, 2025). It is a gas-only part and the usual answer when the pilot lights but will not stay lit, because the thermocouple is the safety device that proves a flame is present before gas keeps flowing. The two parts it sits between cost less and more: a pilot light repair is $75 to $175, a gas valve replacement $150 to $300.
- How much does a water heater thermostat replacement cost?Updated 2026-09-25Replacing a water heater thermostat costs $100 to $250 and repairing one $75 to $150, both with labor included, per Fixr's water heater repair guide (August 29, 2025). The gap is small enough that replacement is normally the better buy. Before you pay for either, rule out the cheaper explanation: This Old House lists an unlit pilot or a tripped breaker as the first things to check when there is no hot water, and Fixr prices that kind of no-power fault at $50 to $400.
- What does venting a gas water heater cost?Updated 2026-09-22Basic gas venting costs $300 to $500, direct venting $500 to $1,000, and a power vent $300 to $600 plus $300 to $500 for the electrical work it needs, according to This Old House (June 2026). Fixr (January 2026) puts a power vent at $300 to $1,000. Fixr's three size-specific guides (40, 50 and 75 gallons, January 2026) carry a fourth figure, $3,400 to $10,200, that sits five to ten times above every other published range.
- Is a longer water heater warranty worth the money?Updated 2026-09-23Standard tank warranties run 6 to 10 years per Fixr (January 2026), against an expected life of 8 to 12 years. Manufacturers cover defects, not wear, and require registration within 30 days. A home warranty costs about $564 a year for basic cover plus $75 to $125 per service visit, per This Old House (June 2026), and typically excludes rust, corrosion and sediment, which are the three things that actually kill a tank.
- What size water heater do you need?Updated 2026-09-22Fixr (January 2026) puts a 40-gallon tank at 1 to 4 people; This Old House (June 2026) says 2 to 3 people need 40 to 50 gallons and 3 to 4 need 50 to 60. For the same family of four, one rule says 40 gallons and the other says 60. Headcount is a poor guide, because what empties a tank is simultaneous use. The number that settles it is the first-hour rating.
- How old is my Whirlpool water heater?Updated 2026-10-08Whirlpool is a licensed name, not a manufacturer. InspectApedia states that Whirlpool water heaters are manufactured under licence by American Water Heater Company of Tennessee, and that the limited warranty comes from that manufacturer rather than from Whirlpool. American Water Heater was bought by A.O. Smith by 2006, so a Whirlpool plate reads by the A.O. Smith rule: the first four digits are the year and then the production week. Fast Water Heater's example for the family, 1220, decodes to week 20 of 2012.