1. What is a 7 GPM Tankless Water Heater?

Definition: A tankless water heater that can provide up to 7 gallons per minute (GPM) of hot water, suitable for medium to large households.

Purpose: This calculator helps determine if a 7 GPM electric tankless heater meets your household's hot water demands.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Total flow rate (gallons per minute)
• \( Q_i \) — Flow rate of each fixture being used simultaneously

Explanation: The calculator sums the flow rates of all fixtures that might run simultaneously to determine peak demand.

3. Importance of Proper Sizing

Details: Undersized heaters cause inadequate hot water, while oversized units waste energy. 7 GPM models typically serve:

• 2-3 bathrooms
• Kitchen and laundry
• Families of 3-5 people

4. Using the Calculator

Tips: Enter the number of each fixture type that might run simultaneously. Default values represent a typical household.

5. Frequently Asked Questions (FAQ)

Q1: What if my total exceeds 7 GPM?
A: Consider a larger unit or staggering hot water use. Electric models above 7 GPM may require significant electrical upgrades.

Q2: What temperature rise can I expect?
A: A 7 GPM electric unit typically provides ~45°F rise (from 50°F to 95°F). For higher temps, flow rate decreases.

Q3: What electrical requirements are needed?
A: Most 7 GPM units require 3x 40-50 amp 240V circuits (total ~28-36 kW).

Q4: Can I install multiple units?
A: Yes, parallel installation can increase capacity but requires professional installation.

Q5: How does this compare to gas tankless?
A: Gas models typically provide higher flow rates but require venting and gas lines.