Water Heater Replacement Cost: Tank vs Tankless
A tank water heater costs $600 to $1,800 installed, while tankless units run $1,500 to $4,500. The right choice depends on your household's hot water demand and how long you plan to stay in the home.
Tank versus tankless: the core price gap
Water heater replacement cost splits into two clearly different price bands depending on system type. A conventional tank water heater is the cheaper upfront option; a tankless (on-demand) unit costs more to install but uses less energy over time.
| System type | Installed cost | Typical lifespan |
|---|---|---|
| Tank water heater | $600 – $1,800 | 10–15 years |
| Tankless water heater | $1,500 – $4,500 | 20+ years |
Why tankless costs more to install
Tankless systems often need upgraded gas lines, electrical capacity, or venting that a straightforward tank swap doesn't require. That's the main reason installation cost for tankless models runs meaningfully higher even before the unit price itself is factored in. Homeowners typically spend around $2,200 for a mid-range tankless installation, compared to roughly $1,200–$2,000 for a standard tank replacement.
Efficiency differences that affect the real cost
| Factor | Tank | Tankless |
|---|---|---|
| Efficiency | ~60–65% | ~85–95% |
| Standby heat loss | Yes — keeps water hot constantly | None — heats on demand |
| Typical annual energy savings (tankless vs tank) | — | 25–40% |
A large household with heavy, spread-out hot water use tends to see the biggest payback from switching to tankless. A smaller household with modest usage may not recoup the higher upfront cost within the unit's lifespan.
What else affects the price
- Fuel source — gas units typically cost less to operate but require an existing gas line; electric units are usually cheaper to install but can cost more to run.
- Permits — required in most U.S. jurisdictions for a water heater replacement; often bundled into contractor quotes but worth confirming.
- Removal of the old unit — should be included in an installed quote; ask explicitly if it isn't itemized.
- Capacity — a tank sized for your household's peak usage avoids running out of hot water, but oversizing adds unnecessary cost.
Is your quote reasonable?
For a standard tank replacement, a professional installed quote in the $1,200–$2,000 range is typical. For tankless, expect $2,000–$3,500 for a mid-range residential unit unless your home needs significant gas line or electrical upgrades, which can push costs toward the top of the range. If a tankless quote comes in dramatically higher than $4,500 without a clear reason (major electrical work, whole-house sizing for multiple bathrooms), ask for an itemized breakdown.
See also our HVAC replacement cost guide if you're planning multiple home system replacements at once, since bundling labor visits can sometimes reduce total cost.
Last updated: August 2026