There may be no water in the water tank (Model CM24T-1), or the water supply may not be connected or turned on (Model CM24P-1). The tank model will display "Refill Water Tank" when empty. Be sure that the tank is full and that the water supply is connected and turned on. A loud buzzing noise may also occur if the pre-ground coffee button has been pushed, but no coffee is loaded in the ground coffee chute. With power to the coffee system turned on, pour ground coffee in the ground coffee chute.