Upon arrival, customer advised me that the business had no hot water because the hot water heater was malfunctioning. I have to brief diagnostic. I determined that the hot water heater needs to be replaced however to make note this is a Chick-fil-A and there is a gas system that powers the entirefacility. System operates off an auto. Facility. System operates off an automatic circulating tank and the tank was receiving no error code however it just was not heating. I advised the customer that I would need to do a diagnostic which would include making sure the gas was being received the proper way and there was also no obstructions with the water line. After diagnostic, I advised customer that I would build an estimate to replace the hot water heater and it would take about one day to complete so the customer requested that we be able to do the job overnight or after business hours. I advised customer that I agreed and I would be willing to do the job overnight if that’s what it took o