hot water is pouring back into the tank

This could be a problem with the water flow valve. When the water is heated and ready to dispense, a pressure pump fill the hot water tank with air, but there is a flow valve to open and direct it to the dispenser in the pod. The valve may not be opening and the water flows back into the tank. This also happens if the water flow needle is clogged. If you pinch the tank tube it will flow out Be careful if the water flow is also clogged it can spray hot water instead. Unfortunately no one has the process to open a Kerig to get inside and replace this flow valve. Not that easy