However, Section 422-14 of the National Electric Code reads:

“b) Storage type water heaters. All fixed storage type water heaters having a capacity of 120 gallons or less  shall have a branch – circuit rating not less than 125 percent of the nameplate rating of the water heater.”

The chart below shows the recommended circuit breaker size for the maximum residential heater wattage.  The maximum wattage and rated voltage are shown on the water heater data plate.

Since a water heater acts as a continuous duty service appliance, (the elements usually heat for an extended period of time) the service wires get warm, increasing electrical resistance and requiring more amperage draw.  If the circuit breaker, permissible by code, is a quick acting circuit breaker it can trip regularly and cause inconvenience and aggravation.

Therefore, our installation instructions use the word RECOMMENDED rather than REQUIRED.

Recommended for Amperage
Max	Max Volts	Max	Max Volts
Watts	120V	208V	240V	Watts	208V	240V
600	10A	5A	5A	3500	25A	20A
750	10A	5A	5A	3800	25A	25A
1000	15A	10A	10A	4000	25A	25A
1250	15A	10A	10A	4500	30A	25A
1500	20A	10A	10A	5000	35A	30A
2000	25A	15A	15A	5500	35A	35A
2500	30A	15A	15A	6000	40A	35A
3000	35A	20A	20A

 

Consult the local electric power company to determine the correct electrical hook-up in order to meet local utility and building codes.