How Many Watts Does A Water Heater Use?

When you're enjoying a hot shower or soaking in a warm bath, you probably don't think about "how many watts does my water heater consume?" But understanding the power consumption of your electric water heater can help you better understand your electricity bill.

Water Heater Power

In most cases, power consumption is measured in watts (W), and you can find the power rating of your water heater in the product manual and on the product itself. The power consumption of household water heaters typically ranges from 1500 watts to 5500 watts.

Estimate Water Heater Electricity Consumption and Cost

First, determine the daily time you use your water heater for heating and the cost per kilowatt-hour (kWh) of electricity.

You can calculate the electricity consumed by your electric water heater using the following formula:

Monthly energy consumption (kWh) = (Power (W) × Daily usage hours (H) × 30) ÷ 1000.

Assuming you have a 3500-watt electric water heater that you use for 2 hours a day, your monthly energy consumption would be: (3500 × 2 × 30) ÷ 1000 = 210 kWh/month.

If the local electricity price is 12 pesos per kilowatt-hour, your monthly electricity bill would be: 210 × 12 = 2520 pesos.

For storage-type electric water heaters, the electricity consumed during water heating and insulation also needs to be considered.

Check the product manual to find the product's ε (inherent energy consumption coefficient).

Calculation formula: Actual 24-hour power consumption = ε × Q. Q = 0.015 * storage tank capacity + 0.8.

For example, if your water heater capacity is 60L and ε = 0.6, then Q = 0.015 × 60 + 0.8 = 1.7. The 24-hour power consumption ≈ 0.6 × 1.7 = 1.02 kWh.

Through these simple calculations, you can get a general idea of the role your water heater plays in your monthly electricity bill, allowing you to better save energy.