Water heater - 120v/single pole breaker

Why? I did not verify if elements were changed to 120v. TIA.

why what…there should be a double pole 30 amp breakers 10 gauge wiring somewhere for that WH.

Will still work but it will take a lot longer to heat the water, cutting the voltage in half from 240 to 120 will have only 1/4 of the listed output.

what if the elements were changed to 120v?

Why would this be done in the first place?

No idea, they didn’t have a 2 pole CB? By cutting the voltage in half the current is also cut in half so that’s why it can operate on a 20 amp circuit.

So what if elements were changed to 120v?

Heater would operate normally but only at the 120 volt output of the new element.

Occasionally, I’ll see a 20-amp circuit breaker on a 4500-watt water heater. While this is technically correctly sized, it leaves little room for overcurrent and does not meet the NEC 125% load guideline.

That’s correct, it will work but according to the NEC the branch circuit needs to be a minimum of 25 amps for a 240 volt, 4500 watt HWH. (4500/240*125%=23.4 amps)

I would note that the heater in the OP is running off of a 120 volt, single pole 20 amp CB.

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How do you know this, did you follow the cable to the WH?

Title of this thread: “Water heater - 120v/single pole breaker”. Joshua started this thread maybe he can answer that question.