If a Keurig coffee maker does not brew, take out and replace the water reservoir, flush out the water line, perform a hard reset, unclog the exit needle and clean out mineral deposits. If these methods don't work, contact Keurig for technical support.
Lift out the reservoir completely, and set it back in place to ensure it attaches to the magnet at the base. If the machine still does not brew, run water through the Keurig several times with no K-Cup present to flush out the water line. You can also perform a hard reset by turning the power off, unplugging the machine and waiting some time before plugging it in again. Ensure the machine has plenty of time to heat up before attempting to brew a cup of coffee.
Coffee grounds can clog the exit needle, also known as the K-Cup pin, thereby preventing the machine from brewing. Turn off the machine, and use an unfolded paperclip or a toothpick to carefully push out any debris from the needle. Mineral deposits may prevent brewing if the machine is not de-scaled every six months. To de-scale a Keurig, run a cup of vinegar or de-scaling solution through the machine. Be sure to run water through the Keurig before brewing to take out the residual vinegar.