Quick answer: Replacing a standard tank water heater costs about $1,200–$2,500 installed (unit $400–$900 + labor $600–$1,500). Tankless runs $2,500–$5,000+ installed. The unit itself is cheaper than the install — most of the cost is labor, permits, and code upgrades. This is one job where a licensed plumber is usually worth it (gas/water/venting), but knowing the numbers keeps you from overpaying.
Cost by Type
| Type | Unit | Installed (total) |
|---|---|---|
| Tank (gas/electric, 40–50 gal) | $400–$900 | $1,200–$2,500 |
| Tankless (gas) | $1,000–$2,000 | $2,500–$5,000+ |
| Heat-pump (hybrid) | $1,500–$2,500 | $2,500–$4,500 |
What Drives the Price
Labor and local rates, whether gas/venting or electrical needs upgrading to meet code, permit fees, and removal of the old unit. Switching from tank to tankless costs more because of gas-line and venting changes.
Tank vs Tankless: Is Tankless Worth It?
Tankless lasts longer (~20 years vs ~10–12), saves space, and gives endless hot water, but costs more upfront. For a straight replacement on a budget, a quality tank is the value pick. For a long-term home, tankless can pay back over time.
Should You DIY It?
Usually no — water heaters involve gas, venting, or 240V wiring and a permit in most areas. This is the kind of job our water guide flags for a pro. Where you save is buying smart and getting 2–3 quotes.