Hi,I changed the anode rod in my 40 US gallon standard vent, Ruud propane water heater, because of bad taste in the water. I shut off the water, changed the rod, turn the water back on and opened the hot water taps to let out the air. After the air stopped coming out of the taps,I shut them off. I believe this is the right way to do this job. Any way after almost a week now I am still getting air out of the hot taps when they are turn on. Never had air before the change. Dosent happen every time. Thanks for your answers, Noel