Should I repair or replace my water heater?

Replace if the tank is leaking. Otherwise compare the repair with a new heater and the age with the tank warranty. A small repair within the warranty leans repair; a large one past it leans replace.

How do I know if the tank is leaking?

Check the relief valve, the drain valve and the pipe connections first. If they are dry and water runs down the jacket from underneath, the tank has failed.

Is a dripping relief valve a tank leak?

No. The temperature and pressure relief valve is a part, and a safety device. If it discharges, a plumber should find out why. Never cap or plug it.

What is the 50% rule?

A rule of thumb: if a repair costs half or more of a new heater, replacing can make more sense. It is not a standard, which is why the calculator shows the share and the reason.

How long should a water heater last?

HyrePlumber holds no lifespan dataset. The tank warranty on the label or rating plate is the maker’s own figure, so the calculator compares age with that.

What do I do if the heater is leaking now?

Close the cold-water valve into the heater, then turn off its breaker or set the gas control to off. Keep away from water near outlets, and call a plumber.

What temperature should it be set to?

CPSC urges 120°F against scalds; CDC advises storing hot water above 140°F against Legionella. A thermostatic mixing valve delivers tempered water from a hotter tank.

HyrePlumber tools

Water heater: repair or replace?

Pick what failed, then type the repair and replacement bids and the tank warranty from the label.

120°F the setting CPSC urges against scalds US Consumer Product Safety Commission, Tap Water Scalds (CPSC Publication 5098), retrieved September 5, 2026. Check the delivered temperature at a tap on any service visit.

If the tank itself is leaking, replace the water heater: the vessel cannot be patched. For any other part, compare the repair bid with the replacement bid and the heater’s age with its tank warranty. A repair at half a new heater, past the warranty, leans replace. Smell gas? Leave and call 911 from outside.

Work out repair or replace

A check on two bids. Nothing is stored or emailed.

— Call

— Repair share

— Why

What this assumed —

A check on two bids, not a diagnosis. A leaking tank is always a replacement.

If water is leaking or you smell gas, do this first

Gas smell. Leave the building. Do not touch switches or use a phone inside. Call 911 and the gas utility from outside.

Water on the floor. Close the cold-water valve on the pipe into the heater, then turn off the breaker or set the gas control to off. Keep away from water near outlets.

Relief valve discharging. The temperature and pressure relief valve is a safety device. Never cap or plug it. Call a plumber to find out why it opened.

Worked examples

Three failures, run through the calculator

Tank leaking

Any age, any price: replace. The vessel cannot be patched.

Element on a young heater

A $200 repair against an $1,800 replacement is 11%, at 3 years on a 6-year warranty: lean repair.

Element on an old heater

A $1,000 repair against $1,800 is 56%, at 10 years on a 6-year warranty: lean replace.

Repair share = repair bid ÷ replacement bid. 50% is a rule of thumb, not a standard. The prices and warranty are examples; type yours.

A leaking tank cannot be repaired

The tank is a steel pressure vessel with a glass lining. There is no field repair for a hole in it.

Why it cannot be patched. When the lining fails and the anode rod is used up, the steel corrodes wherever the lining is imperfect. Sealing one visible spot leaves the rest of the wall.

What looks like a tank leak but is not. The relief valve, the drain valve at the bottom, the pipe connections at the top, and condensation on a gas unit. All four are repairable.

How to tell. With the valves and connections dry, water running down the outside of the jacket from underneath is the tank.

What failed, and what it means

What failed	What it is	What to ask
Tank body	The pressure vessel	Replace. Ask about sizing the next one on first-hour rating.
Heating element	A replaceable part in an electric heater	Was scale the cause? Is the other element sound?
Anode rod	A sacrificial rod that protects the tank	What condition was it in, and when should it be checked again?
Relief valve	The temperature and pressure safety valve	Why did it open: temperature, pressure or a worn valve? Is an expansion tank needed?
Gas valve, thermocouple or igniter	Gas control parts	Gas work is licensed work. Is the venting checked on the same visit?
Drain valve or connections	Fittings, not the tank	A repair, not a reason to replace.

HyrePlumber’s checklist, not a diagnosis or a price.

The anode rod decides how long the tank lasts

What it is

A magnesium or aluminum rod inside the tank that corrodes so the steel does not. It is used up by design.

Why it matters

Once the rod is gone, corrosion moves to the steel wherever the lining is imperfect. Checking the rod can extend the tank’s life.

What to do

Ask your plumber to check it at a service visit and tell you its condition. The tank must be isolated and drained correctly: it is a plumber’s job.

Check the temperature setting at the same visit

CPSC: “The U.S. Consumer Product Safety Commission (CPSC) urges all users to lower their water heaters to 120 degrees Fahrenheit.” CPSC says 140°F water can cause a third-degree burn in six seconds.

CDC: “Legionella grows best between 77°F–113°F (25°C–45°C).” CDC advises storing hot water above 140°F.

Both, with a mixing valve. CDC names valves that mix hot and cold near the tap. Ask for the delivered temperature at a tap, in writing.

What to ask the plumber at the heater

Where exactly is the water coming from?
Tank, valve or fitting. Ask them to show you.
What caused it?
Not only what failed: scale, pressure, temperature or age.
Is the tank still under warranty?
The years are on the label or the rating plate. Parts can carry a separate warranty.
What would a replacement add?
Venting, an expansion tank, a pan and drain, code updates, a permit.
Written diagnosis, separate from the price
So you can get a second bid on the same finding.
Do not accept a repair to a leaking tank
A patched pressure vessel is not a repair.

Questions this calculator answers

Should I repair or replace my water heater?: Replace if the tank is leaking. Otherwise compare the repair with a new heater and the age with the tank warranty. A small repair within the warranty leans repair; a large one past it leans replace.
How do I know if the tank is leaking?: Check the relief valve, the drain valve and the pipe connections first. If they are dry and water runs down the jacket from underneath, the tank has failed.
Is a dripping relief valve a tank leak?: No. The temperature and pressure relief valve is a part, and a safety device. If it discharges, a plumber should find out why. Never cap or plug it.
What is the 50% rule?: A rule of thumb: if a repair costs half or more of a new heater, replacing can make more sense. It is not a standard, which is why the calculator shows the share and the reason.
How long should a water heater last?: HyrePlumber holds no lifespan dataset. The tank warranty on the label or rating plate is the maker’s own figure, so the calculator compares age with that.
What do I do if the heater is leaking now?: Close the cold-water valve into the heater, then turn off its breaker or set the gas control to off. Keep away from water near outlets, and call a plumber.
What temperature should it be set to?: CPSC urges 120°F against scalds; CDC advises storing hot water above 140°F against Legionella. A thermostatic mixing valve delivers tempered water from a hotter tank.

Sources and methodology

Figures dated September 5, 2026. Last reviewed September 29, 2026.

Tap Water Scalds (CPSC Publication 5098) (US Consumer Product Safety Commission, retrieved September 5, 2026). Burn times by temperature and the 120°F recommendation.
Monitoring Building Water (US Centers for Disease Control and Prevention, retrieved September 5, 2026). Growth range 77–113°F, storage above 140°F, mixing valves.
How to use the EnergyGuide label (Federal Trade Commission, retrieved August 23, 2026). Where first-hour rating and yearly cost appear, for the replacement.

Water heater repair and replacement What the job includes and what the bid should say.
Water heater sizing Size the replacement on first-hour rating.
Tank vs tankless payback Replacement is when tankless becomes a real choice.
Is this a plumbing emergency? For water you cannot stop.
Gas line services Gas work is licensed work.

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