Customer States: His pilot on his 20 year old Whirlpool water heater will go out from time to time, it has been happening more often this past month and needs a remedy. Technician Notes: Out today to look into issue with the 20 year old Whirlpool natural gas water heater located in the main level garage. The water heater pilot light will go out intermittently. Customer will have to relight each time this occurs to get hot water. Tested millivolts on the thermocouple. Millivolts are proper. Issue is not related to the thermocouple. Determined the issue to be a failure with the gas control valve. Unitrol/ Robert Shaw brand gas control valve. Managed to locate part on Grainger. Resolution: After recommending a new water heater replacement to the customer due to age of the unit and discussing price. He decided he wants this one repaired, not replaced. Part will need ordered. Once part arrives we will need to schedule up with customer to return and replace the faulty gas control valve. J