Water Heater First Hour Rating (FHR) Explained — What Vancouver Homeowners Need to Know
Published: July 20, 2026 — CANRO Heating & Cooling — Greater Vancouver, BC
What FHR Means
FHR measures how many gallons of hot water a water heater can deliver in the busiest hour, accounting for the tank storage and the recovery rate. A 40-gallon gas tank may have FHR of 67-72 gallons because the burner recovers hot water while you use it. Electric tanks have lower FHR because electric elements recover slower.
Household FHR Needs
1-2 people: FHR 50-60 gallons. 3-4 people: FHR 60-75 gallons. 5+ people: FHR 75-90 gallons. Calculate your peak hour demand by adding up expected simultaneous use: shower (10-15 gal), dishwasher (6-10 gal), washing machine (10-15 gal), and bathroom sink (2-4 gal).
FHR by Type
Gas tank 40-gal: FHR 67-75. Gas tank 50-gal: FHR 70-80. Gas tank 60-gal: FHR 75-90. Electric tank 50-gal: FHR 50-60. Electric tank 80-gal: FHR 65-80. Tankless: unlimited FHR (limited only by flow rate). Choose based on your household peak demand.