THE SHORT VERSION
- A leak from the tank itself means a new heater. A.O. Smith’s service bulletins say a leaking tank cannot be repaired. Leaks at valves, pipe joints and element gaskets usually can, and some “leaks” are only condensation.
- Almost everything else is a replaceable part: relief valve, thermocouple, gas valve, igniter, heating elements, thermostats, anode rod, dip tube, drain valve. Fixr’s installed ranges for these run from about $100 to $325, and up to $750 for a heating element.
- Age is the tiebreaker. Tanks are expected to last roughly 8–15 years, depending on whose figure you use. Rheem and ENERGY STAR both say to start planning a replacement around year 10.
- Rheem’s 50% rule of thumb: replace when a repair would cost more than half the price of a new heater. For a tank installed at $1,600–$2,400, that line is $800–$1,200, which a single part repair rarely reaches.
- Replace on your schedule, not the tank’s. ENERGY STAR warns that an emergency replacement can cost more and narrow your choices.
The tank decides, the parts don’t
A tank water heater is a steel pressure vessel with a set of bolt-on parts around it. The parts wear out and are designed to be replaced. The vessel is not: once it leaks, the heater is finished. So the first job is always to find out whether the problem is a part or the tank.
If it is a part, three things decide whether fixing it makes sense: how old the heater is, what the repair costs compared with a new heater, and whether the warranty covers any of it. Rheem, one of the largest US makers, puts it the same way: the answer “depends on your unit’s age, the nature of the problem, and how repair costs compare with replacement costs.”
Sources: Rheem (8–12 years), ENERGY STAR (10–12), DOE Energy Saver (10–15); Rheem, “Water Heater Lifespan: When to Repair vs. Replace” (2026); Home Depot water heater installation cost guide; Rheem and ENERGY STAR on replacement planning.
Start with where the water is coming from
Water on the floor is the most common reason people ask this question, and it has several possible sources. A.O. Smith’s service bulletin on puddles lists them: condensation, the drain valve, the temperature and pressure (T&P) relief valve, piping at the inlet and outlet, the gas valve’s threaded connection, the gaskets around electric elements, and the tank. Only the last one is a death sentence. Its verdict is blunt: “Leaking heaters cannot be ‘repaired’.”
Rule out condensation first
Gas heaters make water as they burn. A.O. Smith says a typical home water heater produces about half a gallon of water vapor per hour of burner operation, and when cold incoming water chills the tank, some of it condenses and drips onto the burner area or the floor. It is most common after a long hot-water draw, and newer, more efficient heaters condense more than old ones. A.O. Smith’s test:
Dry the floor
Wipe up all the water under and around the heater.
Turn the gas valve to “Pilot”
This stops the main burner but keeps the pilot lit. On an electric heater, skip this test: electric tanks don’t burn fuel, so there is no flue condensation.
Wait 8 hours
Don’t use hot water in the meantime if you can avoid it.
Look again
No new water means it was condensation. New water means a leak: check the fittings, and if they are tight and dry, the tank is leaking.
Then trace the leak upward
- Drip from the end of the relief valve’s discharge pipe: the valve is opening. That is usually a pressure problem in the house, not a bad heater. See relief valve leaking.
- Water at the threads where the relief valve screws into the tank: a technician can remove the valve and reseal it. If water seeps from the welded fitting (the “spud”) itself, A.O. Smith says it is not repairable and the heater should be replaced.
- Wet pipe joints on top: loose or corroded connections are repairable. In humid weather, sweating cold pipes can drip too.
- Drain valve dripping: close it firmly; if it still drips, the valve is replaced.
- Water around an electric element panel: A.O. Smith says element gaskets can be replaced and the threads resealed.
- Rust stains or wet spots on the jacket, seams or bottom with all fittings dry: the tank. Rheem says pooling water around the tank body “often indicates internal corrosion,” and that a compromised tank “may suddenly release more water.”
Common failures: usually repairable, or time to replace
Manufacturer service manuals are the best guide to what is meant to be fixed in the field. Bradford White’s service manual for its standard gas tanks, for example, has step-by-step replacement procedures for the thermocouple or thermopile, pilot assembly, piezo igniter, gas valve, burner, dip tube and anode. It has none for the tank. Rheem says heating elements, thermostats and anode rods “are all designed to be swapped out.”
| Failure | What you notice | Usually | Why |
|---|---|---|---|
| Tank body leak (wall, seam, bottom) | Water with dry fittings; rust streaks on the jacket | Replace | Corroded from inside. Manufacturers say a leaking tank can’t be repaired. |
| Welded fitting (spud) seeping | Water where the relief valve or a pipe enters the tank | Replace | The spud is welded to the tank. A.O. Smith: not repairable. |
| Bulged or domed tank bottom | Crooked pipe nipples on top; domed bottom | Replace | A sign of severe overpressure. A.O. Smith says repair is not possible. |
| T&P relief valve dripping or leaking | Water from the discharge pipe or valve threads | Repair | The valve is a cheap part, but find why it opened: often thermal expansion or high supply pressure. |
| Thermocouple or thermopile | Pilot lights but won’t stay lit (gas) | Repair | A standard field-replaceable part in Bradford White’s manual. |
| Pilot assembly or igniter | Igniter clicks with no flame, or pilot won’t light | Repair | Replaceable as a unit. Power-vent and tankless models use electronic igniters and flame sensors, also replaceable. |
| Gas control valve (gas thermostat) | No main burner, wrong temperature, or a status-light code | Repair | Replaced as a unit; Bradford White lists it for a failed magnet, overheat cutoff or bad calibration. |
| Heating element | Lukewarm or no hot water (electric) | Repair | Each element unscrews from the tank. Rheem: designed to be swapped out. |
| Electric thermostat | No heat, or water too hot | Repair | One per element, behind the side panels. |
| Anode rod | Discolored water; rod worn to its core wire when inspected | Repair | A wear part. Rheem suggests replacing it every 3–4 years. |
| Dip tube | Hot water runs out or turns lukewarm sooner than it used to | Repair | Bradford White: a cracked tube isn’t repairable, so the tube is replaced. |
| Drain valve | Drips at the bottom spigot | Repair | A low-cost part, often plastic. |
| Sediment | Rumbling, popping, slower recovery | Flush or delime | Maintenance, not a part failure. Heavy buildup on an old tank is a warning sign. |
Sources: A.O. Smith technical bulletins 15, 41, 51 and 52; Bradford White service manual 238-51542-00C (2019); Rheem repair-vs-replace and warning-signs articles. “Usually” means for a tank that is otherwise sound; age and price can still tip the decision.
Tankless and heat pump models
The same logic applies with different parts. DOE’s Energy Saver guidance says tankless heaters have “easily replaceable parts that may extend their life by many more years.” The expensive component on a tankless unit is the heat exchanger; Rheem’s residential gas tankless warranty covers it for 15 years, parts for 5 and labor for 1. On a heat pump water heater, the costly part is the sealed refrigerant system, and ENERGY STAR requires at least a 6-year warranty on it for certification. Because these heaters cost more to replace, a given repair is a smaller share of a new one, so repairing makes financial sense more often. For tankless fault codes, see tankless problems by symptom.
What common repairs cost
No one publishes measured local repair prices, so treat any range as rough. The table puts three kinds of number side by side: what the part itself costs at a big-box store, and the installed ranges published by two lead-generation sites, HomeAdvisor and Fixr. They disagree, which tells you how much prices vary.
| Repair | Part at Home Depot | HomeAdvisor, installed | Fixr, installed |
|---|---|---|---|
| T&P relief valve | about $14 | $20–$200 | $100–$250 |
| Thermocouple | about $12 | about $150 | $150–$325 |
| Gas control valve | about $143 | about $350 | $150–$300 |
| Heating element (4,500 W) | about $62 | $200–$300 | $200–$750 |
| Electric thermostat | about $31 | $150–$200 | $100–$250 |
| Anode rod | not listed | $50–$150 | $125–$300 |
| Dip tube | about $25 | $25–$175 | $100–$250 |
| Drain valve | about $6 | not listed | $100–$200 |
| Flush the tank | none | about $200 | not listed |
Part prices: Rheem PROTECH and Everbilt replacement parts on homedepot.com, checked October 4, 2026; prices change and your model may need a different part. Installed ranges: HomeAdvisor water heater repair cost guide (updated June 2026, based on its customer surveys) and Fixr water heater repair cost guide (updated August 2025). Both are lead-generation sites, not measured local data.
The pattern is clear even though the ranges disagree: the part is usually a small slice of the bill. Most of what you pay is the trip, the diagnosis and the labor. Draining the tank (for a dip tube, anode or lower element) adds time. That is why a $12 thermocouple can turn into a $150–$325 invoice, and why one visit that fixes two things costs less than two visits.
Age: how long each type is expected to last
Expected life figures differ by source, and water quality and maintenance move them a lot. These are the published numbers:
| Type | Rheem | ENERGY STAR | DOE Energy Saver |
|---|---|---|---|
| Gas or electric tank | 8–12 years | 10–12 years | 10–15 years |
| Heat pump (hybrid) tank | not stated | 13–15 years | not stated |
| Tankless | 15–20+ years | not stated | more than 20 years |
Sources: Rheem, “Water Heater Lifespan: When to Repair vs. Replace” (March 2026); ENERGY STAR, “What Goes into the Cost of Installing a Heat Pump Water Heater?” (2024); DOE Energy Saver, “Tankless or Demand-Type Water Heaters” (archived June 2026). See how long water heaters last for what shortens or stretches these.
Rheem says units over 10 years old “are more likely to experience additional failures soon after one is fixed,” and that internal corrosion may not be visible from the outside. That is the real cost of repairing an old tank: you can pay for a new element and still have the tank fail months later. Rheem recommends beginning replacement planning around year 10, and ENERGY STAR says the same.
Find the real age
Don’t guess from when you bought the house. The manufacture date is on the rating plate or encoded in the serial number, and each brand uses its own code. Bradford White’s online warranty check returns the manufacture date from a serial number. For other brands, see how to read the serial number.
The 50% rule, and when it misleads
Rheem’s rule of thumb: “if repair costs exceed 50% of the price of a new unit, replacement is almost always the better investment. The same applies if you’ve needed multiple repairs in a short timeframe.” It also says repair makes sense when the unit is under 6–8 years old, shows no tank corrosion or structural leaks, and the repair costs “well below 50%” of replacement. Treat it as a heuristic from a company that sells new heaters, not a standard.
Its weakness for tanks is the one shown in the chart above: single-part repairs almost never reach $800. So the rule mostly catches stacked repairs, after-hours rates and tankless or heat pump repairs. For an ordinary tank, use it together with age and the tank’s condition. Three hypothetical cases:
6-year-old gas tank, pilot won’t stay lit
A thermocouple at about $150 installed is 150 ÷ 1,600 = 9% of the low end of a new tank. The heater is young and the fault is a part. Repair.
12-year-old electric tank, lower element burned out
An element at $250 is 250 ÷ 1,600 = 16%, well under the 50% line. But the tank is past ENERGY STAR’s 10–12-year range, so another failure is likely. Either is reasonable: repair it and get replacement quotes now, or replace it on your schedule. If you replace, this is the moment to price a heat pump model (next sections).
9-year-old tank, water at the bottom seam
The repair price doesn’t matter. A tank leak can’t be fixed. Replace, and check the warranty first: some tanks carry 9- or 10-year coverage.
Signs a tank is near the end
ENERGY STAR’s list of red flags matches Rheem’s closely. None of these alone proves the tank is failing, but on a heater near 10 years old, any of them is a reason to get replacement quotes now:
- Leaks or moisture at joints, seals or seams, or rust on the tank or around the water lines. ENERGY STAR: a water heater is a closed system, so any moisture outside it means something is breaking down.
- Rumbling, popping or crackling during heating. This is usually sediment or lime on the tank bottom. A.O. Smith says flushing or deliming treats it; Rheem says left alone it can make the tank overheat or fail. See water heater noises.
- Rusty or brown hot water. ENERGY STAR and Rheem treat it as a sign of corrosion inside the tank or a spent anode. A.O. Smith says lining failure is rare and iron bacteria in the water is the most common cause. If only the hot water is discolored, ask for the anode to be checked before you condemn the tank. See smelly or discolored water.
- Less hot water than before. Often a failed element, thermostat or dip tube, all repairable; sometimes heavy sediment taking up space in the tank. See running out of hot water.
- Repeat service calls. Rheem treats several repairs in a short time as a sign of broader wear.
Check the warranty before you pay for anything
Tank warranties have separate terms for the tank, the parts and the labor, and they differ by brand and model. Rheem’s certificate for one of its hybrid models, for example, covers the tank and parts for 10 years and labor for 1. Look up your exact model; details are in our warranty guide.
- A leaking tank in warranty usually gets you a heater, not an installation. A.O. Smith’s residential warranty says it will furnish a new heater but the owner pays labor, removal and other costs unless state law says otherwise.
- Parts in warranty are often free; the visit isn’t. That can make a repair on a young heater cheap.
- Anode rods are excluded as consumables in A.O. Smith’s terms, and failures from sediment buildup are excluded too.
- Transfer rules vary. Bradford White’s warranty extends to later owners while the heater stays where it was installed. A.O. Smith’s residential warranty is not transferable.
- Claims usually go through a contractor. Bradford White says warranty claims are submitted by the service professional through a Bradford White distributor.
When a new heater pays some of its own way
The biggest efficiency step comes from changing technology, not from a newer copy of the same tank. ENERGY STAR puts most traditional water heaters at a Uniform Energy Factor (UEF) of 0.63–0.95 and certified heat pump water heaters at 3.3–4.1, because a heat pump moves heat from the surrounding air instead of making it.
ENERGY STAR estimates a certified heat pump water heater saves a household of four about $550 a year compared with a standard electric tank, with a payback of about 2.7 years. Its assumptions: electricity at $0.146/kWh, $1,503 more up front than a standard electric tank, and a 13-year life. Your savings depend on your rates and use, and switching from gas is a different calculation; see heat pump water heaters.
That changes the math on an aging electric tank. Spending $250 on an element for a 12-year-old tank buys time; spending the difference on a heat pump model ($2,500–$5,000 installed on Home Depot’s figures, against $1,600–$2,400 for a tank) buys lower bills too. Note that the federal 25C tax credit ended for improvements made after December 31, 2025. Check rebates from your utility or state before you decide.
Plan the replacement before the tank decides for you
ENERGY STAR warns that a sudden failure can force an emergency replacement “which can be more expensive, and typically limit your replacement options to inefficient models.” A heat pump model may also need ordering time and a longer install, according to ENERGY STAR. Planning removes both problems.
Note the age and model
Photograph the rating plate and decode the serial number.
Decide what you want next
Same type, or a switch? Read tank vs. tankless vs. heat pump while you still have hot water.
Get written quotes now
Two or three, for the same job. The FTC advises not to automatically choose the lowest bid and to ask about big differences. Our guide to comparing quotes shows what to check line by line.
Keep a fallback
Know where the water shutoff and the gas valve or breaker are, and keep the best quote on file so a failure becomes one phone call.
For what a replacement typically costs and why quotes differ, see water heater replacement cost.
What to ask a plumber who recommends replacement
A replacement recommendation is often right, especially for a leaking or old tank. These questions help you confirm it, and a good plumber will answer them without hesitation.
Questions to ask
- Where exactly is the water coming from? Can you show me, or send a photo?
- Is it the tank, or a valve, gasket or fitting? If a fitting, is it threaded (resealable) or welded to the tank?
- If it isn’t leaking: which part failed, and what would that repair cost, in writing?
- How old is the heater according to the serial number?
- Have you checked the warranty? Would the manufacturer supply a new heater or the part?
- If the relief valve is dripping, have you checked the water pressure and whether we need an expansion tank?
- What would replacement include: permit, haul-away, expansion tank, drain pan, venting or electrical changes?
- Can you quote both options so I can compare?
Common questions
Can a leaking water heater tank be repaired?
No. A.O. Smith’s service bulletins say a leaking tank should be replaced, and Rheem says once a tank deteriorates from the inside, replacement is the only safe option. Leaks at valves, pipe threads or element gaskets are a different matter and are usually repairable.
Is it worth repairing a 10-year-old water heater?
Sometimes, for a cheap part on a sound tank. Rheem says units over 10 years old are more likely to fail again soon after a repair, and both Rheem and ENERGY STAR suggest planning a replacement around year 10. A reasonable middle path is to make the small repair and get replacement quotes now.
What is the 50% rule for water heaters?
It is Rheem’s rule of thumb: if a repair would cost more than half the price of a new unit, replacement is almost always the better investment. For a tank installed at $1,600–$2,400, the line is $800–$1,200. It is a heuristic, not a standard.
How much does it cost to replace a thermocouple or heating element?
Fixr lists $150–$325 installed for a thermocouple and $200–$750 for a heating element; HomeAdvisor lists about $150 and $200–$300. The parts themselves cost about $12 and $62 at Home Depot. Most of the bill is the visit and labor.
Why does my relief valve keep dripping?
Usually because pressure builds as the water heats and has nowhere to go, called thermal expansion, or because the incoming water pressure is too high. A.O. Smith says a sudden large discharge of very hot water points to a thermostat problem instead. A technician should find the cause; don’t cap or plug the valve.
Does the warranty pay for a new water heater if the tank leaks?
If the tank is still in its warranty period, the manufacturer usually supplies a replacement heater, but you typically pay the labor to install it. Terms differ by brand and model, so check the certificate for your model number.
Is water under my water heater always a leak?
No. Gas heaters can drip condensation, especially after a long hot-water draw. A.O. Smith’s test is to wipe the floor dry, set the gas valve to Pilot, wait 8 hours and look again. Dry means condensation.
Sources
Sources checked October 4, 2026. Prices, codes and rebates change. Check current details with your installer and local permit office.
- Water Heater Lifespan: When to Repair vs. Replace (March 2026) ↗ · Rheem
- 5 Signs Your Water Heater Is Going Bad (December 2025) ↗ · Rheem
- When Should You Replace Your Water Heater? (2024) ↗ · ENERGY STAR
- What Goes into the Cost of Installing a Heat Pump Water Heater? (2024) ↗ · ENERGY STAR
- Heat pump water heaters ↗ · ENERGY STAR
- Heat pump water heaters: benefits and savings ↗ · ENERGY STAR
- What is Uniform Energy Factor and why does it matter? (2024) ↗ · ENERGY STAR
- Residential water heaters key product criteria ↗ · ENERGY STAR
- Tankless or Demand-Type Water Heaters (archived copy, June 2026) ↗ · U.S. Department of Energy, Energy Saver
- Technical Bulletin 15: Condensation ↗ · A.O. Smith
- Technical Bulletin 51: Puddle on floor ↗ · A.O. Smith
- Technical Bulletin 52: Leaking temperature and pressure relief valve ↗ · A.O. Smith
- Technical Bulletin 45: Thermal expansion ↗ · A.O. Smith
- Technical Bulletin 41: Bulging heater ↗ · A.O. Smith
- Technical Bulletin 46: Premature failure ↗ · A.O. Smith
- Technical Bulletin 13: Mineral build-up ↗ · A.O. Smith
- Technical Bulletin 21: Discolored water ↗ · A.O. Smith
- Technical Bulletin 36: Not enough hot water, electric ↗ · A.O. Smith
- Service manual 238-51542-00C, Defender FVIR gas water heaters (2019) ↗ · Bradford White, hosted by G.T. Sanders
- Warranty Center and warranty FAQs ↗ · Bradford White
- Residential limited warranty 100286376 Rev D (retailer copy, 2018) ↗ · A.O. Smith
- Certificate of limited warranty, hybrid electric water heater AP18539-1 (2017) ↗ · Rheem, hosted by Home Depot
- Residential tankless gas water heater warranty guide ↗ · Rheem
- Energy Efficient Home Improvement Credit ↗ · IRS
- How To Avoid a Home Improvement Scam ↗ · Federal Trade Commission
- Water heater installation cost guide (installed price ranges) ↗ · Home Depot
- Water heater repair cost guide (updated June 2026; lead-generation site) ↗ · HomeAdvisor
- Water heater repair cost guide (updated August 2025; lead-generation site) ↗ · Fixr
- Rheem PROTECH gas control valve SP14270H (product page) ↗ · Home Depot
- Everbilt 24 in. gas water heater thermocouple EBTC-24 (product page) ↗ · Home Depot
- Rheem PROTECH 4,500 W heating element SP10698MH (product page) ↗ · Home Depot
- Rheem PROTECH upper thermostat SP11699 (product page) ↗ · Home Depot
- Rheem PROTECH T&P relief valve SP12574 (product page) ↗ · Home Depot
- Rheem PROTECH dip tube PT12933 (product page) ↗ · Home Depot
- Rheem PROTECH drain valve SP12159B (product page) ↗ · Home Depot