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Temperature Rise Calculator
Quick answer: Temperature rise = desired hot-water setpoint − incoming (groundwater) temperature. Example: 120°F − 50°F = 70°F rise. Colder water means a bigger rise and a bigger unit.
Estimates for planning only — not professional, engineering, plumbing, gas or electrical advice. Confirm sizing, venting, gas and electrical with a licensed installer and local code.
Typical groundwater
Figures below are illustrative examples (2026-10-29), not quotes or guarantees.
Roughly 35–45°F in northern winters, 50–60°F in mild regions, 65–75°F in hot southern regions. Use your coldest-month value for sizing.
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