Breaker Size For Electric Hot Water Heater

Just follow the three simple steps below to choose the right model and size you need.

Breaker size for electric hot water heater.

Now in order to choose an electric breaker multiply the current draw of the water heater with 125 per cent in order to determine the size of the breaker you will need. 1 or 2. Multiply the value for current by 125. Electric water heaters require a 240 volt dedicated circuit which serves only the water heater and no other appliances or devices.

First lets start with the nec code for this water heater application. So it won t work as effectively as it needs. If you can plug the heater into a regular wall outlet the specified voltage should be 120 volts. Wire a hot water heater with wire that s sized to accommodate the heater s current requirement.

For example a 20 amp hot water heater needs 12 gauge wire a 25 amp hot water heater requires 10 gauge wire and a 30 to 40 amp hot water heater requires 8 gauge wire. But with a 25 amp breaker the 20 amp water heater will only cover 80 of the total capacity of the circuit breaker. The circuit wiring typically includes a 30 amp double pole breaker and 10 2 non metallic nm or mc cable. I agree with you that this water heater circuit is not a typical configuration and the common circuit for a new home is 10 copper wire protected by a 2pole 30amp circuit breaker however lets look at this application carefully.

Thus the current draw for a 1 500 watt heater is 12 5 amps. This happens because 20 amp from the water heater is more than 80 of the breaker capacity. In the above example we would require a 15 6 amp circuit breaker for our us readers. You can estimate the necessary tank capacity in gallons based on the number of people in the house.

Multiply the current rating of the water heater with 125. Instead you need at least 25 amp. Choose the right tankless electric water heater for you. For a tank style heater household size is a simple indicator of hot water needs.