I have a Rheem model 22V50F1 gas water heater that won't stay lit. It is an attic installation. I've had almost everything tried. Water pressure seems OK, have added an expansion tank on cold intake, replaced gas control valve, etc. Occasionally the pressure relief valve goes off and I get an alarm from the overflow tank. At other times it just stops working. Re-lights OK but could go out in 5 minutes or two days? Being suggested that its too hot in attic - can that be right? If so, how do I add intake air? Cooling the attic is a major expense and I'm already being told that attic ventilation is proper for the size of home. It is Texas and it does get hot up there. I have measured temps up to 145 degrees F.
Any thoughts?