If you are in the market for a new water heater, you might be wondering what size you need. Maybe you run out of hot water in the middle of your shower or you don’t ever run out of water and you think you might be wasting money – heating up more water than necessary.
The U.S. Department of Energy has an easy way for you to determine exactly what water heater will suit your family’s needs. (For tank or storage type water heaters)
What is Your FHR?
First, you must determine your family’s FHR – first hour rating. This is the amount of hot water your family uses in an hour. Think about the busiest hot water hour of the day. How many people take a shower during that hour? What else are you doing that requires hot water?
Use the following information to help you:
- An average shower uses approximately 10 gallons of water. Adjust this if anyone in your family takes longer than usual showers
- Shaving uses about 2 gallons of hot water
- Hand washing your dishes uses about 2 gallons per minute or, for the average family, about 4 gallons to do the dishes
- A dishwasher uses an average of 6 gallons of water
- Your clothes washer takes about 7 gallons of water (if you don’t use hot water to wash your clothes, you can skip this one
Add up all the hot water that is used during the busiest hot water hour of the day in your house. This is your household’s FHR.
Looking for the FHR on Your Water Heater
New conventional tank or storage water heaters are required to have an EnergyGuide label. The label lists the “Capacity” or “First Hour Rating.” If this number is close (within 2 gallons) to your household FHR, you have the correct size water heater. If the number on the water heater is much lower, you should look at purchasing a larger heater. If the number is much larger, you may be wasting energy and money heating up water unnecessarily.
Platinum Plumbing & Heating