Additional garage door openers are an easy way to add convenience to your home. You can buy the simplest ones for about $10 at locksmiths or hardware stores--and they are easy to program. You don't need to match the garage door opener transmitter model-for-model or manufacturer-to-manufacturer; just make sure the frequency matches. Some use coding switches and some are digitally pre-programmed with unique codes to program your garage opener.
Look at the back of your existing garage door opener remote and look for a label that includes the frequency. Purchase a remote control garage-door opener that matches the frequency of your other opener.
Locate the coding switches on the existing remote control transmitter. Unscrew the visor clip and remove the battery compartment cover. If the remote control has them, the keys will be exposed below. They operate like dip switches and may be numbered one through eight.
Open the additional garage door opener and match the dip switches (keys) to the keys on the original remote control transmitter. For example, if switch 1 is up and switch 2 is down, replicate it. The end result is that the dip switches on each remote should match in all transmitters.
Replace the battery cover and visor clip.
Some digital garage door transmitters use a learning mode instead of dip switches. Refer to the instructions that came with the receiver to set it into learning mode. Press the new garage door opener button to program it into the receiver. The receiver will learn your additional garage door opener’s codes and then turn off the learning mode at the receiver.