Water Heater Cost: Complete Guide to Tank, Tankless, and Replacement Pricing

Water heater replacement costs $800 to $1,900 for a standard tank system, averaging ~$1,400 installed. Tankless systems run higher, $1,300 to $4,000, averaging around $2,500. The type you choose, fuel source, capacity, and how much your existing venting, gas line, or electrical needs to change all move you within those ranges.

The equipment itself is often the cheapest part of the job. When you request a quote through Serve Kei, a vetted local plumber prices your actual setup, venting, gas line, panel capacity, so the number reflects your home, not a national average.

Cost at a Glance

Gas units generally cost more than electric to install because of venting requirements. Tankless costs more upfront but lasts longer, 15 to 20 years versus 8 to 12 for a tank system, so fewer replacements over the life of the home.

Tank vs. Tankless

Tank water heaters store and continuously heat 30 to 80 gallons of water, ready whenever you need it. They're the more common choice and the cheaper install, since most homes already have the plumbing, venting, and electrical in place for a straight swap.

Tankless water heaters heat water on demand instead of storing it, using energy only when a tap is open. They take up less space and last longer, but a first-time tankless install often means new electrical circuits (electric models) or a larger gas line and venting (gas models), which is where a lot of the added cost comes from.

Sizing: What Capacity Do You Need?

Tank sizing is based on household size and peak demand:

Tankless units are sized by flow rate (gallons per minute) rather than storage volume. A single-bathroom home typically needs a unit rated for 2 to 3 GPM; a larger home running multiple fixtures at once needs 5 GPM or higher, sometimes two units.

What Affects the Cost

Fuel type. Electric tank units are usually the simplest and cheapest install since they don't need venting. Gas units cost more upfront but generally cost less to run. Switching fuel types, say electric to gas, adds real cost since it means running a new gas line.

Venting. Gas water heaters need proper venting to the outside. If your existing vent is undersized, wrong material, or the unit is being relocated, venting work adds to the labor cost.

Electrical. Electric tankless units draw a lot of power and often need a dedicated circuit or a panel upgrade if your existing panel doesn't have capacity. This is one of the bigger tankless-specific cost drivers.

Location and access. A straightforward swap in the same spot, with existing connections, sits at the lower end. Moving the unit, or installing in a tight attic or crawlspace, adds labor time.

Permits. Many jurisdictions require a permit for water heater replacement, particularly for gas units or any electrical work.

Removal and disposal. Hauling away the old unit is usually a small add-on, but it's worth confirming it's included in a quote rather than billed separately.

Replacement vs. Repair

Most tank water heaters last 8 to 12 years; tankless units last 15 to 20. Repair makes sense for a newer unit with an isolated issue, a bad heating element, a faulty thermostat, a pilot light problem. Replacement is usually the better call when:

A vetted installer can also tell you honestly when a repair still makes sense instead of pushing a replacement you don't need yet.

Getting an Accurate Quote

Have ready: your household size, current fuel type (gas or electric), whether you're switching fuel types or system types, and your water heater's current location. That's what turns a national range into a real number.

Frequently Asked Questions

How much does a new water heater cost?

A standard tank system runs $800 to $1,900 installed, averaging ~$1,400. Tankless runs $1,300 to $4,000, averaging around $2,500.

Is tankless worth the extra cost?

It depends on your usage and timeline. Tankless costs more upfront but lasts roughly twice as long as a tank system and uses less standby energy, so the gap narrows over 15 to 20 years. For a straightforward one-for-one tank swap, tank is usually the lower-hassle, lower-cost choice.

How long does installation take?

A like-for-like tank swap typically takes 2 to 4 hours. A first-time tankless conversion, especially one needing new gas line or electrical work, can take a full day.

What size water heater do I need?

Tank: 30 to 40 gallons for 1 to 2 people, 40 to 50 for 3 to 4, 50 to 80 for larger households. Tankless: sized by flow rate (GPM) rather than storage.

Do I need a permit to replace a water heater?

Often, yes, particularly for gas units. A licensed installer handles this as part of the job in most cases.

How long do water heaters last?

Tank systems: 8 to 12 years. Tankless: 15 to 20 years, with regular descaling in hard-water areas.

Bottom Line

Most homeowners pay around ~$1,400 for a standard tank replacement or roughly $2,500 for tankless. Fuel type, venting, electrical capacity, and whether you're switching system types are what move you up or down from there. Compare complete installed quotes, not just the unit price, since venting and electrical work can account for a large share of the total.

Related reading

National averages are useful for planning. Verify pricing against a quote for your home before treating any range as final.