This test shows a SIO 18 Pro which has an 80 AMP rating. The inlet water temperature was 65 degrees with a 50 degree rise to 115 degrees. The measured flow rate was 3.2 GPM

 

Low Amperage Draw - While running, the temperature remains within 1-2 degrees of the setting and the AMP draw remains consistent at approximately 48 AMPs, or roughly 60% of the maximum.

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No Power Surge - When the unit is shut off and started again, the initial power level reaches a high of 54 AMPs and then settles back to 48 AMPs...no Power Surge!