Size New Water Heater
1 hourCalculate BTU or kW for household demand; check first-hour rating.
Field context
This workflow is part of 4 niche fields
Complete guide for water heater replacement — step-by-step workflow, tools, checklist, and expert tips to get started.
Calculate BTU or kW for household demand; check first-hour rating.
Shut gas/electric and water; drain tank completely.
Set new unit; connect vent, gas/electric, and water lines.
Set 120°F; check vent draft and expansion tank precharge.
Key benchmarks for water heater replacement.
| Household | Tank Size | First Hour Rating |
|---|---|---|
| 1-2 people | 30-40 gal | 40-50 gal FHR |
| 3-4 people | 50 gal | 60-70 gal FHR |
| 5+ people | 75-80 gal | 80+ gal FHR |
Heat pump water heaters cut electric bill 60% in basements.
Check anode every 3 years — extends tank life 5+ years.
Dry-fired elements burn out instantly.