I am unable to light my water heater at experienceing about three (3) feet of water in my house. When I try to light it using the procedures listed on the side. I hear gas flowing but the igniter doesn't spark. I talked to a guy at a local plumbing company and he recommened I replace the thermocouple. Can you tell me if this the recommended repair, where to get said part and detailed instructions or the repair and replace. I am very handy with tools and would like to fix it myself if possible.