First check to see if you have a wall console ( push button ) that has a vacation switch or lock button. Most times your lighted push button will be blinking if that function has been activated. Push and hold the vacation or lock button for approximately five seconds and release. If that was the problem the transmitter should then work. If it’s still not working, try a new battery. Be careful to not disturb the coding switches if present. If still malfunctioning you may check to see if coding switches on the transmitter match the switches on the power unit hanging from the ceiling.