Modern garage door openers are manufactured with a receiver built into the logic board. The receiver allows the garage door to be opened using a wireless remote or wireless keypad. The remote or wireless keypad sends/transmits a signal, radio frequency, to the garage door opener. If the garage door opener recognizes the signal sent, the garage door will open or close. The modern garage door openers work on a rolling code system, meaning the code/frequency changes each time the remote is used to open and close the garage door. Older units used only a single frequency every time the door opened and closed and some used DIP switches to allow the customer to program the code, but it was still a single code unit. The new rolling codes provide enhanced security for your garage door opener.
An external receiver is typically used when the internal receiver has stopped working. The external receiver plugs into the power outlet and then connects to the opener. The connection to the opener is made to the same connections as the wall console. There is a learn button on the external receiver that allows it to be programmed to remotes. Once the external receiver is properly installed and remotes programmed the garage door opener will open and close using the remotes programmed to the external receiver.
Depending on the brand of external receiver, it may require the use of only that brand of remote. For example, if you install a marantec external receiver, you will only be able to use marantec remotes and keypads. There are no universal remotes or keypads that will program to marantec external receivers.
Symptoms of a bad receiver include reduced distance for the remote transmitters and transmitters that do not work at all. If you are experiencing these symptoms, first try replacing the batteries in your remotes. Many times weak batteries in your remote will show the same symptoms as a bad receiver.
There are other options if your receiver for your garage door opener stops working. The first option would be to replace the logic board in the garage door opener. The logic board is the mother board for your garage door opener, and the receiver is a part of the logic board. In most cases this fixes the receiver issue. The other option is to replace the entire garage door opener.
The cost of an external receiver is about $90-$100 for the part plus labor to install and program the receiver and remotes.