Use this tankless water heater installation checklist to prepare your home, choose the right unit, and avoid costly installation mistakes. Covers gas, electric,

For tank water heaters: 1-2 people need 30-40 gallons, 3-4 people need 40-50 gallons, and 5+ people need 50-80 gallons. For tankless: measure by GPM (gallons pe

For tank water heaters, size by First Hour Rating (FHR) — the gallons of hot water it delivers in the first hour of use. A household of 1–2 people needs a 30–40

A new water heater costs $900–$3,000 installed for a standard tank model (40–50 gallon). Tankless water heaters cost $2,500–$5,000+ installed. The total price d