Shower: ~2 GPM · Kitchen faucet: ~1.5 · Tub fill: ~4 · Simultaneous use adds up.
Incoming water temperature
Lower inlet temp = more energy needed to reach setpoint. Affects tankless sizing significantly.
Recommended capacity
50gallon tank
or
3.2GPM tankless
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Gallons / day
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First hour rating
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Peak BTU/hr needed
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Temp rise needed
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BTU/day total
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Recommended size
Annual energy cost comparison — all types
Electricity rate ($ / kWh)
Natural gas rate ($ / therm)
Propane rate ($ / gallon)
Expansion tank
Required by code in most closed plumbing systems — prevents pressure buildup
Expansion tank cost ($)
2–5 gallon thermal expansion tank: ~$40–$80. Required when a pressure-reducing valve is present.
Replacement labor
Swapping existing unit — existing connections, venting, and electrical assumed compatible
Labor cost ($)
Standard tank replacement: ~$250–$500. Tankless: ~$400–$800. Hybrid HP: ~$400–$700 (requires adequate space & airflow).
Permit & inspection ($)
Most jurisdictions require a permit for water heater replacement: ~$50–$150.
Haul-away of old unit
Disposal fee for old tank
Haul-away fee ($)
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Equipment cost
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Annual energy
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10-yr total cost
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Est. installed
Cost breakdown
Equipment—
Expansion tank—
Installation labor—
Haul-away—
Annual energy cost—
10-year energy cost—
Installed + 10-yr energy—
Sizing based on 20 gal/person/day avg usage · FHR = daily demand × 0.7 peak factor · Energy costs use DOE test procedure methodology · Prices exclude tax and delivery