Upon arrival, customer informed me that she was not getting any hot water from her hot water heater. The heater was a tankless RX 37. She said it just randomly stopped heating and she does not know why. First thing I asked, the customer was for her breaker was so I could check the breaker and make sure she was properly amped.M after checking the breaker. I advised the customer that it was under amped the heater that she had she needed more amperage. I explained to the customer that the heater was working because it being under amp doesn’t stop it from working. It just makes it work harder which decreases the efficiency and eventually leads to short lifespan. Customer said that heater has only been two years old. I advised customer that in order to be The most efficient she would need to get the heater that is designated for three double pole 40. Advised the customer that the correct heater would be an RX 27. Customer said she would prefer buying her own heater from Home Depot rather th