Multiply the current rating of the water heater with 125.
Breaker size for electric hot water tank.
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.
But with a 25 amp breaker the 20 amp water heater will only cover 80 of the total capacity of the circuit breaker.
In the above example we would require a 15 6 amp circuit breaker for our us readers.
At the water heater the black circuit wire connects to the black wire lead on the water heater and the white circuit wire connects to the white wire lead on the water heater.
Just follow the three simple steps below to choose the right model and size you need.
You can estimate the necessary tank capacity in gallons based on the number of people in the house.
First lets start with the nec code for this water heater application.
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.
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.
Rheem tankless electric water heaters make it easy to enjoy instantaneous continuous hot water space saving design and significant energy cost savings.
Of course pairing up the right circuit breaker according to the water heater demands is useful.
Some large heaters draw up to 50 amps requiring 6 gauge wire.
A 40a breaker would be appropriate to protect 8 wiring but it would not be preferred to protect a standard water heater at 40a.
The 20 amp size breaker is used for dedicated appliance.
The 15 amp size breaker is used in general circuit wiring.
So it will work consistently and in a stable way.
For a tank style heater household size is a simple indicator of hot water needs.
Choose the right tankless electric water heater for you.
1 or 2.
Understanding water heater wiring.
Electric water heaters require a 240 volt dedicated circuit which serves only the water heater and no other appliances or devices.
Wire a hot water heater with wire that s sized to accommodate the heater s current requirement.