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Determine the correct water heater size for your home based on household size, bathrooms, and hot water usage patterns.
The right tank size depends on your household size and hot water usage patterns. Here are general guidelines:
| Household Size | Tank Size (Gas) | Tank Size (Electric) |
|---|---|---|
| 1-2 people | 30-40 gallons | 40-50 gallons |
| 2-3 people | 40-50 gallons | 50-60 gallons |
| 3-4 people | 50-60 gallons | 60-80 gallons |
| 5+ people | 60-80 gallons | 80+ gallons |
Electric water heaters typically need larger tanks because they have slower recovery rates than gas units.
FHR measures how much hot water a tank can deliver in the first hour when starting full.
Your FHR requirement should match your peak hour demand. A family of 4 typically needs an FHR of 60-80 gallons.
Tankless units are rated by flow rate (GPM) at a specific temperature rise.
2-5 GPM units work for one fixture at a time. Good for point-of-use applications.
5-10 GPM units handle multiple fixtures. Choose based on peak simultaneous demand.
A family of 4 typically needs a 50-60 gallon gas water heater or 60-80 gallon electric unit. Look for a First Hour Rating of at least 60-80 gallons.
Add up hot water usage during your busiest hour. For example: 2 showers (20 gal each) + dishwasher (14 gal) = 54 gallons peak demand.
No. Oversized tanks waste energy heating water you don't use. Size for your actual needs, with a small buffer for guests.
For whole-house use, most homes need 5-8 GPM. Calculate your peak simultaneous usage and add 20% buffer.