Did you read the directions in the instructions? I just recently bought one myself and binded one of the receivers to the transmitter last night:

1) Turn the transmitter on

2) Hold the "ON" button on the receiver (the little button that's inside the chimney looking thing on the receiver)

3) Turn the power on for the receiver

4) You will see the LED on the "ON" button of the receiver start to flash slowly, keep holding the button for 2 more seconds

5) Release the "ON" button on the receiver, and press the "bind" button on the transmitter

6) The LED on the receiver should now flash very fast, binding the receiver to the transmitter.

Hope that helped...