The Allister Type IIA opener does not use a "learn" button to program the remotes as most openers do as of May of 2011. The Allister uses a group of dip switches located on an external receiver and inside the remote controls. It is a good idea to change your programming codes periodically to help prevent someone from figuring your code on a different dip switch remote. Reprogramming an Allister Type IIA does require temporarily removing the receiver from the unit.
Position a step ladder under the rear of the Allister garage door opener. Loosen the screws securing the rectangular receiver to the back of the opener with a Phillips screwdriver.
Pull the receiver away from the opener. Look on the back of the receiver for a small square cover. Pry the cover off with a regular screwdriver to reveal the programming dip switches.
Slide the bottom cover of the Allister remote control off the unit to reveal the dip switches in the remote.
Move the individual dip switches up or down as necessary on the receiver. The switches will push up or down with your finger. Reposition the dip switches on the remote to match the switch placement inside the receiver.
Place the covers back onto the remote control and the back of the receiver. Slide the prongs on the receiver back under the terminal screws of the opener motor head. Tighten the screws with the Phillips screwdriver.
Push the control button on the remote control to operate the opener. If the opener does not operate, one or more of the dip switches do not match. Go through the entire process again and make sure that both the receiver and the remote dip switches match exactly.