I know I need to replace the pressure tank because water comes out of the schrader valve for the air bladder. What I don't know is why with a mix of hot and cold at an open faucet, when the pump shuts off there is a five second shot of really hot water. Does anyone have any ideas. 30/50 switch on the well pump, a smaller pressure tank but like I said I think the air bladder is shot. I drained the tank and did my best to recharge it and the pump isn't running as often anymore. The hot water surge has me baffled.

Do you have an expantion tank on your water heater? If you do this might be the cause of the five second surge.