Repair it, or replace it?

Answer from what you can see and what the plumber quoted. The verdict comes with its reasoning listed line by line, so you can disagree with a specific step rather than with a black box.

One symptom settles it on its own

Water pooling under the tank, coming from the tank rather than from a fitting above it, is the end of that appliance. A storage water heater is a pressure vessel with a glass lining over steel; once the lining is breached the steel corrodes from the inside, and by the time it weeps the wall is gone. No part replaces the wall. Everything else on this page is a matter of degree, and that one is not, which is why it overrides age, warranty and maintenance history in the verdict above.

The others are genuinely arguable. A pilot or igniter that will not stay lit is a cheap part on an otherwise sound appliance. Rumbling and popping is the sound of water flashing to steam under a sediment layer, which is a maintenance failure rather than a mechanical one, and a flush sometimes buys years. Rusty or sulphurous hot water usually means the anode rod is spent, and how much life is left depends on how long it has been spent — which is unknowable, which is why it scores moderately rather than decisively.

Why the quote in your hand outranks everything else

Published repair prices are a range, not a prediction: $150–$700 for a tank^[1] and $300–$1,300 for a tankless unit^[1], spanning everything from a thermocouple to a control board. The number that decides your case is the one on the piece of paper in front of you, which is why the tool asks for it and says plainly that it is the missing lever when you leave it blank.

Framing it as a share of replacement is what makes it actionable. A $180 repair on a six-year-old tank is obviously worth doing. The same $180 on a fourteen-year-old tank is buying a few months on an appliance already past the 15-year end of its expected life^[2], and the replacement it defers has not got any cheaper. The tool computes that share against a straightforward like-for-like swap using the same installed-cost engine as the front page, so the two tools cannot quietly disagree with each other about what replacement costs.

Primary document · quoted verbatim · retrieved 2026-08-06

Most tankless water heaters have a life expectancy of more than 20 years. They also have easily replaceable parts that may extend their life by many more years. In contrast, storage water heaters last 10–15 years.

U.S. Department of Energy, Energy Saver — energy.gov/energysaver/tankless-or-demand-type-water-heaters

Two things to take from that, in opposite directions. The federal range is where the verdict gets its sense of “near the end”, so a tank in year thirteen is being judged against a published expectation rather than against a rule of thumb. But the sentence is about equipment classes, not about your appliance: it knows nothing about your water hardness, your anode rod or whether the tank was ever flushed, and those move real service life further than the range itself is wide.

Two things deliberately do not enter the verdict. Nothing here knows your water chemistry, which moves service life more than any input on this page. And nothing here knows whether you are about to sell the house, which changes the calculation completely — a repair that is poor value over ten years can be entirely correct over ten months.

Questions people actually ask

My water heater is leaking. Can it be repaired?

If the leak is at a fitting, a valve or the relief line, yes. If water is coming from the tank itself, no — that is the steel shell failing under pressure, and there is no part that fixes a hole in a pressure vessel. This is the one symptom that overrides everything else here, including a young appliance still under warranty.

At what point is a repair not worth it?

A useful rule is the share of a replacement the repair represents. Typical tank repairs run $150–$700 against a straightforward fifty-gallon replacement at $700–$3,100. Once a quote passes about half of replacement on an appliance near the end of its life, the repair buys a fraction of an appliance and none of the warranty.

How long should a water heater last?

Federal guidance gives storage tanks 10 to 15 years and tankless units more than 20. Water chemistry moves those numbers a long way in both directions: hard water and a neglected anode rod shorten a tank considerably, and a flushed, maintained tank in soft water outlives the guidance.

What is an anode rod and does it matter?

It is a sacrificial metal rod inside the tank that corrodes so the steel does not. When it is used up, the tank starts corroding instead. Replacing one costs a fraction of a tank and is the single most effective thing anybody does to extend a storage water heater — and almost nobody does it, which is why so many tanks fail at the low end of their range.

Sources for the numbers above

HomeGuide — https://homeguide.com/costs/water-heater-installation-cost (retrieved 2026-08-06)
U.S. Department of Energy, Energy Saver — https://www.energy.gov/energysaver/tankless-or-demand-type-water-heaters (retrieved 2026-08-06)