I have a state select water heater the model number is P64020LS. The serial number is A00131689. I have had this water heater in my house for 13 years. I would like how to correct this problem. My hot water heater runs for 3-4 days and then I will not have hot water. Then I have to press the red reset button and it runs for 3-4 days. Then it will shut down again.