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Heat & Tap
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Water Heater Guides

Cost, lifespan, maintenance, troubleshooting, code and rebates. The things you need once you own one.

By Brijon M., Owner and writer, MadGrey LLC·Last updated October 6, 2026·How we pick →

The six guides most people need: what a water heater actually costs (we present ranges and name who published them), how long they last (10 to 15 years for a tank, up to 20 for tankless), how to flush a tank and a tankless unit, what to do when it runs cold, breaker and wire sizing, and the 2026 rebate position now that the federal credit has ended.

The roundups on this site help you buy. This section is about everything after that: running one, maintaining it, troubleshooting it, and the two questions people ask before they buy — what it costs and how long it lasts.

Before you buy

Maintenance

When something is wrong

Technical

The two guides worth reading before you spend anything

[How long they last](/guides/how-long-they-last), because it reframes the purchase. The tank is not what fails — the anode rod runs out and then the tank rusts through. That one fact turns a replacement decision into a maintenance decision.

[Replace or repair](/guides/replace-or-repair), because a surprising number of water heaters get replaced for a fault that is a cheap part. A failed thermocouple, a dead upper element, a stuck thermostat — all of those are repairs, and all of them get quoted as replacements.

On cost figures

What goes in with it

A water heater is a system, not a box. These are the parts that go in with it, and the ones people discover they need halfway through the job.

  • Expansion tank

    Required by code on a closed system, which is most homes with a pressure-reducing valve.

  • Drain pan

    Cheap insurance anywhere the tank sits above something you care about.

  • Anode rod

    The part that decides when the tank leaks. Replacing it is the highest-value hour of maintenance there is.

Questions people actually ask

›How long do water heaters last?
Storage tanks about 10 to 15 years and tankless units up to 20, consistently across the sources we checked. What decides where you land is the anode rod and your water chemistry rather than the brand. Full guide.
›How often should I flush my water heater?
A storage tank: annually, or every six months in hard water. A tankless unit: annually as the manufacturer baseline, more often in hard water, and it is a requirement with warranty implications rather than good practice.
›Is there still a water heater tax credit in 2026?
Not the federal 25C credit — it expired on December 31, 2025 for equipment placed in service after that date. State HEAR programs and utility rebates still exist and vary completely by zip code. Rebates.
›Why does my water heater run out of hot water so fast?
Five common causes, and only one is the tank being too small: a failed lower element, a broken dip tube, a stuck thermostat, heavy sediment, or genuinely insufficient capacity. Check them in that order. Troubleshooting.
›What size breaker does a water heater need?
It depends entirely on the unit. A 120 V mini tank uses a standard 15 A outlet; a 240 V resistance tank typically a 30 A circuit; an EcoSmart ECO 27 needs three 40 A breakers and draws 113 A. Full table.