A:the problem is an emergency device it is a combination temperature& pressure releif valve DO NOT CAP IT OFF!!!! THIS IS A DEVICE THAT LETS YOU KNOW THAT YOUR HEATER IS EITHER GETTING TO HOT OR YOUR PRESSURE IS TO HIGH! I would call a plumber A.S.A.P to take a look at it, the valve can also just be bad and need replacement it is not unusual for them to get coroded and need to be replaced. Haveing said that you can do it yourself but the heater should be chacked for proper working order. Good luck
