How to tell whether your water heater needs a repair or a full replacement, what each costs in 2026, and how tank and tankless compare.
A water heater rarely dies quietly — you get lukewarm showers, strange noises, or a puddle on the floor first. The question is whether you're looking at a quick repair or the end of the unit's life. Get it wrong and you either throw good money after bad or replace a heater that had years left.
This guide covers the warning signs, a simple repair-or-replace framework, what replacement costs in 2026, and how tank and tankless units stack up.
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Match the symptom to the likely fix — then confirm with a plumber, since a leaking tank in particular can escalate fast.
| Symptom | Usually a… |
|---|---|
| No hot water, unit under ~8 years old | Repair (element/thermostat/igniter) |
| Pilot won't stay lit | Repair (thermocouple) |
| Not enough hot water for the household | Repair or resize |
| Rusty water or heavy sediment noise | Often replace |
| Leaking from the tank itself | Replace |
| Unit is 10+ years old with a major fault | Replace |
Rule of thumb: if the repair costs more than half the price of a new unit, or the heater is past its expected life, replacement is usually the better value.
Tankless (on-demand) units cost more upfront but last longer and only heat water when you use it. Tank units are cheaper to install and simpler to service.
| Type | Typical installed cost | Lifespan | Notes |
|---|---|---|---|
| Tank (gas or electric) | $1,200–$3,500 | 8–12 years | Lower upfront, higher standby loss |
| Tankless (gas or electric) | $3,000–$6,500 | 15–20 years | Endless hot water, higher upfront, may need upgrades |
Tankless can require a larger gas line or electrical upgrade, which adds to installation — factor that into the comparison.
Broad national ranges for a fully installed unit as of 2026, including removal of the old heater. Your quote varies with fuel type, capacity, code upgrades, and local labor.
| Unit | Typical installed cost |
|---|---|
| Electric tank (40–50 gal) | $1,200–$2,500 |
| Gas tank (40–50 gal) | $1,500–$3,500 |
| Tankless (electric) | $3,000–$5,000 |
| Tankless (gas) | $3,500–$6,500 |
| Heat-pump (hybrid) tank | $2,500–$5,000 |
A standard tank water heater lasts about 8–12 years; tankless units often last 15–20 years. Regular flushing to clear sediment extends the life of either type.
If the unit is under about 8 years old and the fix is minor, a repair is usually worthwhile. If it's 10+ years old, leaking from the tank, or the repair costs more than half the price of a new one, replacement is the better value.
Installed, a standard tank unit typically runs $1,200–$3,500 depending on fuel type and capacity, while tankless units run roughly $3,000–$6,500. Code upgrades or a new gas line can push tankless installs higher.
Tankless costs more upfront but lasts longer, saves space, and only heats water on demand, which can lower energy use. It pays off best for households with steady hot-water demand and a long time horizon in the home.
A leak from the tank itself can't be repaired and may fail suddenly, so treat it as urgent: shut off the water supply to the heater and call a plumber promptly to limit water damage.
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This guide is general information, not professional advice. Costs and recommendations vary by property, region and provider — always get a qualified local pro to assess your situation.