Sizing a Water Heater for Household Demand

Peak Demand Comes First

Peak demand is the most hot water your home uses at one time — say, a shower running while the dishwasher fills. Sizing to peak demand means the unit can keep up when demand is highest, not just on average.

Count the fixtures that might run together and how much each draws. That snapshot, more than the number of people in the home, is what the unit needs to handle.

Tank vs. Tankless Sizing

Incoming Water Temperature Matters

A unit doesn't heat water from zero — it raises the incoming cold water to your target temperature. In Los Angeles, incoming water temperature varies by season, which changes how hard the unit works in winter versus summer. We factor that in when sizing.

What to Confirm for Your Home

• Which fixtures run at the same time during peak use
• The unit's first-hour rating (tank) or flow rate at your temperature rise (tankless)
• Whether your demand has grown (added bathroom, larger family)
• Whether the unit can recover fast enough for back-to-back use

Unsure What Size You Need?

We assess your actual peak demand and incoming water conditions before recommending a size — so the unit fits how you live.

Or call: (833) 658-8144