Finding a water heater leaking in your home is stressful. The good news? Most leaks start small, and a few quick steps may help limit the damage.
This guide covers what to do now, whether it's an emergency, and what a fix typically costs. ARS®/Rescue Rooter® offers water heater repair and replacement with Emergency Services Available. Call Today: 877-292-4503.
What to Do Right Now If Your Water Heater Is Leaking
If your water heater is leaking, shut off its power or gas, close the cold-water supply valve, and contain the water. This stops the tank from refilling and may help limit damage. The same steps apply to an electric unit or a gas water heater leaking from the bottom.
- Turn off the breaker for an electric unit, or set the gas control to OFF.
- Close the cold-water shutoff valve on the pipe above the tank.
- Open a hot water faucet to relieve pressure.
- Soak up water, move valuables, and take photos.
- Call a plumber to find the source.
If you smell gas: Don't flip any switches. Leave the house, then call 911 or your gas company from a safe place outside. The Pipeline and Hazardous Materials Safety Administration's federal gas safety guidance says that if "you smell gas, move to a safe location and call 911."
Is It Really a Leak or Just Condensation?
Condensation is moisture that forms on the outside of the tank when cold incoming water chills the metal. It's especially common on gas water heaters. The A. O. Smith leak guide notes, "Condensation will go away when the tank of water is hot."
To check water under the water heater, try the dry-and-watch test. Towel the tank and floor dry, wait an hour, and check again. A thin film all over likely means condensation, while a growing spot at the bottom of the water heater likely means a leak.
Where Is the Water Coming From?
Water runs down, so a puddle at the bottom doesn't always start at the bottom. Check from the top of the tank down with a flashlight. This table may help explain why your water heater is leaking from the bottom.
| Leak Source | How to Spot It | Typical Next Step |
|---|---|---|
| Inlet and outlet fittings | Drips or rust where pipes connect on top | Often tightened or replaced by a pro |
| T&P relief valve or discharge tube | Water at the end of the tube near the floor | Have a pro check water pressure |
| Heating element gasket (electric only) | Moisture around the element access panels | Pro replaces gasket |
| Drain valve | Drips from the spigot near the base | Pro replaces valve |
| Tank body | Seeping from the outer shell or under the unit | Replace the water heater |
A heating element is the metal rod that heats water in an electric model. Its gasket is the rubber seal around it.
Drain Valve or Loose Fittings
The drain valve is the spigot near the base used to empty the tank. Older plastic drain valves can wear out, a common reason for a water heater leaking from the bottom. Don't overtighten a plastic valve, since that can crack it.
Fittings are where the hot and cold pipes connect on top of the tank. A loose fitting can drip down the side and pool at the base. Both issues are usually smaller repairs.
Temperature and Pressure (T&P) Relief Valve
The temperature and pressure (T&P) relief valve is a safety valve that releases water when pressure or heat gets too high. InterNACHI explains how a relief valve works: it opens if "pressure in the system exceeds 150 PSI, or temperature exceeds 210° F."
The valve's discharge tube ends near the floor, so its release is often mistaken for a tank leak. If your water heater is leaking water from the bottom, check this tube first. Never cap or plug it, because that blocks the safety release.
Ongoing discharge may point to high pressure or a missing expansion tank. An expansion tank is a small tank on the cold-water line that absorbs extra pressure as water heats. Learn the signs of high water pressure so you can describe them to your plumber.
The Tank Itself
Sediment is sand-like mineral buildup that settles on the tank floor. Over the years, minerals in water can corrode the inside of the tank, according to ENERGY STAR. Signs your hot water tank is leaking from the bottom include:
- Rusty or discolored hot water
- Water seeping from the tank jacket
- Rumbling noises while the water heats
- A water heater over 10 years old, which may be nearing the end of its lifespan
Age matters too. The ENERGY STAR replacement guidance says, "If you suspect your water heater is more than 10 years old—it is time to consider replacing it."
A leaking tank body typically calls for a water heater replacement. As one manufacturer's leak bulletin puts it, "If all fittings are tight and the tank is leaking, replace the water heater."
Is a Leaking Water Heater an Emergency?
Treat every leak as urgent, and some as true emergencies. After shutdown, use these lists to decide your next move.
Call now if:
- Water is gushing.
- You smell gas.
- The tank body is leaking.
- The T&P valve keeps discharging.
- Water is near outlets or the electrical panel.
Can usually wait for a scheduled visit (after shutdown):
- A slow drip is coming from the drain valve.
- A slow drip is coming from a fitting.
ARS offers emergency plumbing services seven days a week, with immediate phone response.
Why You Shouldn't Wait on a Slow Leak
A slow drip may seem minor, yet the water can travel where you can't see it.
- Hidden damage: A steady drip can soak drywall and subfloor.
- Mold growth: The EPA mold and moisture guide says, "It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth."
- Sudden failure: A failing tank can suddenly release much of the water it holds.
According to Triple-I data on homeowners water damage claims, "About one in 60 insured homes has a property damage claim caused by water damage or freezing." That figure covers all water damage, with water heaters as one possible cause.
If nearby floors or walls feel damp, consider water leak detection and repair to find hidden moisture.
How Much Does It Cost to Fix a Leaking Water Heater?
The cost to fix a leaking water heater depends on where the leak starts. Repairs typically cost far less than replacement.
These are national ranges, and local quotes vary. ARS provides upfront written estimates before work begins.
Repair Costs
Valve, fitting, and gasket repairs sit at the low end. Angi's guide to average tank repair costs compares tankless fixes at "between $100 and $1,300" to "$100 and $500 to repair a tank heater." Emergency or after-hours visits may add fees.
Replacement Costs
According to ARS national service data (January 2025 through January 2026), a standard tank water heater replacement typically ranges from about $2,300 to $3,500. The price depends on capacity and installation requirements. ARS reports tankless installations typically run about $4,400 to $6,500.
| Option | Typical Range (ARS) | Good Fit When |
|---|---|---|
| Standard tank replacement | About $2,300 to $3,500 | You want a like-for-like swap at a lower upfront cost |
| Tankless installation | About $4,400 to $6,500 | You want hot water on demand and a smaller footprint |
Considering an upgrade? Explore tankless water heater installation. ARS also offers financing options.
Repair or Replace: A Simple Rule
ARS uses a simple rule. Is the heater over 10 years old? If so, and a repair quote is more than half the cost of a new unit, replacement usually makes more financial sense.
As noted above, a leaking tank body usually means replacement, since a pro can't safely patch a pressurized tank. Younger tanks may still be under the manufacturer's tank warranty, so check the serial number on the label.
ARS recommends professional water heater service once a year to help catch small issues early. Your thermostat setting matters too - the Department of Energy recommends 120ºF.
The Pro Service Plan includes two HVAC preventive maintenance visits per year. Plumbing maintenance, including a water heater flush, is available as an optional add-on.
Get Your Leaking Water Heater Fixed
ARS/Rescue Rooter is available seven days a week. Our trusted, background-checked technicians give you an upfront written estimate before work begins.
We protect your home with shoe covers and drop cloths, and our work is backed by the Exceptional Service Guarantee. If you're unsatisfied within one year of your original invoice, we'll make every effort to meet your expectations.
To schedule a repair or water heater replacement, give us a call.
Frequently Asked Questions
Cold water is usually fine once the heater's supply valve is closed, and our guide to troubleshooting no hot water may help in the meantime. Avoid hot water until a pro finds the source, especially if the tank is leaking.
For a minor drip from a fitting or valve, a short shower may be OK. If the tank body is leaking, shut the heater down and wait for repair.
A leaking valve or fitting can be fixed, and the heater may run for years. A leaking tank can fail at any time, so plan to replace it soon.
The usual causes are a worn drain valve, T&P valve discharge, a worn heating element gasket, or a corroded tank.
On electric models, the lower heating element's gasket may be worn. The fix involves shutting off the power, draining the tank, and having a pro replace the gasket.
Washington's state insurance regulator guidance notes, "Homeowner insurance usually covers sudden leaks, but may not cover gradual leaks." Coverage depends on your policy, so call your insurer. .
