The 801 heater is an 8 year warranty. Your problem is that Home Depot now carries GE heaters. My Home Depot still takes Reliance back and replaces them with GE, but in your case, since they do not want to do it, take it to Home Base. They now stock Reliance and use the serial number in place of a receipt. With both HD and HB, I have exchanged many Reliance water heaters and have never had a receipt.