A gas tank water heater costs $1,700 to $3,200 installed; gas tankless runs $3,000 to $6,500. The tankless saves a typical family about $117 a year in gas, which means a payback of nearly 20 years. Meanwhile the heat pump hybrid, at $2,500 to $5,000, saves $645 a year over an electric tank and pays back in under 3. The tankless pitch is real physics wrapped in bad economics, unless your situation matches a few specific profiles.
| Type | Installed Cost | Lifespan |
|---|---|---|
| Electric tank | $1,200 – $2,600 | 10–13 yrs |
| Gas tank | $1,700 – $3,200 | 10–13 yrs |
| Gas tankless | $3,000 – $6,500 | 15–20 yrs |
| Electric tankless | $1,200 – $5,800 | 15–20 yrs |
| Heat pump hybrid | $2,500 – $5,000 | 12–15 yrs |
The spreads deserve explanation. Gas tankless is expensive because the venting and gas line are part of the job: a tankless burner pulls 150,000 BTU or more against a tank's 40,000, so the meter and line sometimes need upsizing, and the stainless category III vent runs by the foot. Electric tankless spans $1,200 to $5,800 for the opposite reason: the unit is cheap, but a whole-house model draws 100 to 150 amps, and if your 200-amp panel can't feed it, the electrical work dwarfs the heater.
Every water heater carries a UEF, uniform energy factor, on its yellow EnergyGuide label: the fraction of energy that actually lands in your hot water. Annual cost is just your household's hot-water energy divided by UEF, times your fuel price. A typical 3-to-4 person household uses about 4,600 kWh-equivalent of delivered hot water a year.
Run the four contenders at national energy prices ($1.65 a therm, $0.175 a kWh):
| Type | UEF | Fuel Used/yr | Cost/yr |
|---|---|---|---|
| Gas tank | 0.64 | 245 therms | $405 |
| Gas tankless | 0.90 | 174 therms | $288 |
| Electric tank | 0.92 | 5,000 kWh | $875 |
| Heat pump hybrid | 3.5 | 1,314 kWh | $230 |
The tankless elimination of standby loss saves 71 therms, $117 a year at these prices. Against the $2,300 upfront premium, that's a 19.7-year payback on a unit that itself lasts 15 to 20. Efficient? Genuinely. A good investment? Not at these numbers. Where gas is pricey, above $2.50 a therm in much of the Northeast and California, the payback compresses toward 12 years and the decision gets closer.
Resistance electric tanks are the most expensive way to heat water that isn't an open flame under a kettle. At $0.175 a kWh, a family of four spends $875 a year. The heat pump hybrid, at UEF 3.5, moves heat from the room instead of making it and gets the same job done for $230. The $645 annual difference retires an $1,850 purchase premium in 2.9 years. Over a 13-year tank life, total cost of ownership comes to roughly $6,740 for the hybrid against $13,275 for the electric tank.
Heat pump hybrids have two quirks worth knowing before you commit. They're taller than tanks they replace, so closet fits need checking. And they cool and dehumidify the space around them by a few degrees, a feature in a Florida garage and a bug in a Minnesota basement you'd rather not chill. In cold spaces, units default to hybrid mode, which blends in resistance elements and lands the real UEF between 2 and 3.
Enter your gas and electric prices; get annual operating cost and payback for any two types, using the same UEF math as the EnergyGuide label.
Water Heater Cost Calculator →Tank sizing runs on first-hour rating, the gallons of hot water the unit delivers in the first hour. Family of four: a 50-gallon gas tank (FHR around 80) or a 65-to-80-gallon electric. Tankless sizing runs on GPM at winter temperature rise: two simultaneous showers plus a dishwasher wants 6.5 GPM or better at a 70°F rise, and if your January inlet water is 40°F, derate the badge number accordingly. A plumber with a bucket and a thermometer at your kitchen sink in January has better sizing data than any brochure.
They save energy, about $117 a year for a typical family switching from a gas tank (245 therms down to 174), but cost roughly $2,300 more installed, so the payback runs nearly 20 years. On the electric side the equivalent upgrade is a heat pump hybrid, which saves about $645 a year over an electric tank and pays back in under 3 years.
A gas unit rated 6 to 8 GPM can, in most of the country, because GPM ratings assume a 77°F rise and winter inlet water cuts real output. In January in Minnesota, inlet water near 40°F drops a 7 GPM unit to under 4 GPM of shower-temperature output. Two simultaneous showers plus a dishwasher usually demands 6.5 GPM or more at full winter rise.
About 3 years against an electric resistance tank. A typical family's hot water drops from roughly 5,000 kWh a year (UEF 0.92 tank) to 1,314 kWh (UEF 3.5 heat pump), saving about $645 a year at $0.175 per kWh. The purchase premium runs about $1,850, and 13-year ownership totals about $6,740 versus $13,275.
A 50-gallon gas tank or 65-to-80-gallon electric tank. Gas burners recover roughly twice as fast as electric elements, so they need less stored volume. Peak-hour demand is the sizing standard: a family of 4 typically peaks near 80 to 90 gallons of hot water in an hour on laundry-plus-showers evenings.
Gas tankless units need category III stainless venting, often a bigger gas line (they draw 150,000 to 199,000 BTU/hr against a tank's 40,000), and code-mandated condensate drainage. In tight installs the venting run alone can run four figures. The unit itself is only about a quarter of that $6,000.