Gas vs. Electric Tankless Water Heater Cost: Which Is Cheaper in 2026?

Gas tankless water heaters cost $1,200 to $3,500 installed and $15 to $30 per month to operate in most U.S. markets. Electric units run $700 to $2,500 installed and $30 to $60 per month. Gas costs more to install but less to run. Electric is simpler to buy and easier to install, until a panel upgrade enters the picture.

Run your numbers through our tankless water heater cost calculator for a comparison adjusted to your ZIP code.

Unit price comparison

Installation cost comparison

Gas tankless water heaters cost $1,200 to $3,500 fully installed. Key cost drivers are venting (often $200 to $500 for direct-vent concentric pipe), gas-line work ($150 to $700 if the line needs extending), and plumber labor ($300 to $800). Condensing gas units also need a condensate drain, adding a small amount to the job.

Electric tankless water heaters cost $700 to $2,500 fully installed. The unit itself is cheaper, but a whole-house model drawing 24 kW or more frequently requires a panel upgrade from 100 to 200 amps. That upgrade alone can run $500 to $2,000, which is why the installed price gap between gas and electric is narrower than the unit prices suggest.

Monthly operating cost comparison

Operating costs track local utility rates. Natural gas runs cheaper per BTU than electricity in most U.S. markets. A household using 60 gallons of hot water per day might pay $15 to $30 per month with a gas unit and $30 to $60 per month with an electric model. The exact figures depend on your region, and that variance matters when you are doing payback math.

Where electricity is cheap, under $0.10 per kWh, or gas rates are elevated, the gap narrows considerably. States like Washington and Oregon, with low hydroelectric power rates, often find electric tankless competitive on a cost-per-BTU basis.

Is electric tankless more energy-efficient than gas?

Electric tankless units convert nearly 99% of input energy to heat, since there are no exhaust losses. Gas models achieve 80% to 96% efficiency depending on whether they are condensing (higher) or non-condensing (lower). But efficiency ratings alone do not determine your bill. What matters is the cost per unit of energy. Natural gas costs less per BTU than electricity in most U.S. markets, which means a 96% efficient gas unit can still produce cheaper hot water than a 99% efficient electric unit when the two fuels are priced at typical rates.

Can I convert from a gas tank heater to an electric tankless?

Yes, but price out the electrical work before you commit. A whole-house electric tankless unit typically draws 24 to 36 kW and needs multiple 40-to-60-amp dedicated circuits. Most homes with a gas water heater have panels sized for gas appliances, not high-kW electric loads. A panel upgrade alone can run $1,500 to $3,500 on top of the unit price. The conversion makes the most sense when you are already planning a panel upgrade for an EV charger or heat pump, or when local electricity rates are genuinely low.

Long-term cost of ownership

• Gas units: Higher upfront and install cost, lower monthly bills, typical lifespan of 20 years with annual flushing and occasional burner service.
• Electric units: Lower upfront unit cost, higher monthly bills in most markets, typical lifespan of 15 to 20 years. Minimal maintenance in soft-water areas; annual descaling needed where water is hard.
• Break-even point: In most U.S. regions, gas saves enough each month to offset the higher install cost within 3 to 7 years.

Which should you choose?

Choose gas if your home already has a gas line, you need to run multiple fixtures at once, and local gas rates are competitive. Choose electric if your home has no gas service, you need a point-of-use unit for a single fixture, or your electricity rate is below $0.10 per kWh. Get quotes from a licensed plumber or electrician before deciding. The right answer depends on your specific home, not a general rule.

Frequently asked questions

What is the downside of an electric tankless water heater? Higher monthly operating costs in most U.S. markets, and the frequent need for a panel upgrade to support a high-kW whole-house model. Electric units also struggle with very high simultaneous demand (multiple showers plus appliances running at once) unless you size up well beyond the stated household average.

Which brands make good gas and electric tankless heaters? Rinnai, Navien, and Noritz consistently rank at the top for gas models. EcoSmart, Stiebel Eltron, and Rheem make well-reviewed electric units. Navien offers a 15-year heat exchanger warranty on their premium condensing gas line, which is worth noting if you are comparing long-term value.

Bottom line

Gas tankless units cost more to buy and install but usually cost less to run each month. In most U.S. markets, that advantage holds over the life of the unit. Electric models are the practical choice for homes without gas service, or for a single-fixture point-of-use install where simplicity matters more than long-term efficiency. Check your local energy rates and your home's existing infrastructure before committing, and use a licensed contractor for the work.

Related guides

• Tankless Water Heater Installation Cost: Full Breakdown for 2026
• Whole House Tankless Water Heater Cost: What to Budget in 2026
• Is a Tankless Water Heater Worth It? Honest Cost vs. Savings Analysis (2026)
• Tankless vs. Tank Water Heater Cost: Full Comparison for 2026
• Cost to Convert to a Tankless Water Heater: What to Expect in 2026
• How Long Do Tankless Water Heaters Last? Lifespan and Maintenance Guide
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