Home › Appliances › Heating & Cooling › Electric Tankless Water Heater › Delaware
How Much Does It Cost to Run a Electric Tankless Water Heater in Delaware? (2026)
Electric tankless heaters draw enormous power, 12 to 36 kW, but only while hot water is flowing. They avoid the standby losses of a tank, saving 10 to 30 percent for most households, but need heavy wiring.
A typical electric tankless water heater (18,000 W) costs $3.42 per hour, or about $76.95 per month at 0.75 hours a day in Delaware. Expensive to run
| Wattage | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| Low (12,000 W) | $2.28 | $1.71 | $51.30 | $624.15 |
| Typical (18,000 W) | $3.42 | $2.56 | $76.95 | $936.23 |
| High (36,000 W) | $6.84 | $5.13 | $153.90 | $1,872 |
Formula: watts ÷ 1000 × hours × price per kWh. Typical use is 0.75 h/day ≈ 4,928 kWh per year.
One hour of an electric tankless water heater (18.0 kWh) is the same electricity as
- 6.0dryer loads
- 180kettle boils
- 400hours of a laptop
- 2,000hours of an LED bulb
In Delaware, with electricity at $0.19 per kWh (source: EIA Table 5.6.A, 2026-06), a typical electric tankless water heater costs $3.42 per hour and about $936.23 per year at 0.75 hours a day. That is about 6% more than the national average for the US ($72.90 per month), because electricity in Delaware costs $0.19 per kWh against $0.18 nationally. Each $1.00 of electricity buys roughly 0.3 hours of use.
How to lower the cost of running a electric tankless water heater
- Install low-flow showerheads. Flow rate directly drives power draw.
- Fix hot water drips. Each one fires the heater.
- Set the outlet temperature to 49 C and skip mixing cold water at the tap.
In standby it draws about 2 W, which adds roughly 18 kWh ($3.33) per year if it is never unplugged.
Frequently asked questions
How much does a tankless water heater cost per month?
About 400 kWh a month for a family of four, roughly 10 to 30 percent less than a tank.
Do tankless heaters use a lot of electricity?
A lot at once, but for short periods. Total use is typically lower than a tank.
Do I need a panel upgrade for an electric tankless heater?
Often yes. Whole-house units need 100 amps or more of dedicated capacity.
Compare with
Cost by region
US states
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Canadian provinces
Related appliances
- Electric Blanket100 W typical
- Heat Pump (Ducted or Mini-Split)2,000 W typical
- Baseboard Heater1,500 W typical
- Portable Fan (Box or Pedestal)50 W typical
Use the generic electricity cost calculator → · Which uses more? Take the quiz →