An automatic garage door opener is a remote controlled device, which opens, closes and locks the garage door at the push of a button. Some even turn the garage light on for you with a timer to turn them off again after a preset time has elapsed.

How a typical opener works.
The hand control for a door opener is like a miniature radio station transmitter, sending out radio waves picked up by the door mechanism (the receiver). The transmitter sends out a radio wave, which is picked up through an antenna by the receiver and converted into an electrical impulse, which eventually activates the door.

The signal sent by the transmitter is not only in a specific frequency but also in a series of coded pulses sent in a certain order. This means that only your transmitter can open your door. Provision is made for altering the transmitting code if necessary, in effect, like changing the lock on a door.

Some do's and don'ts.
When using an automatic door opener:

• Don't - operate control unless door is in view. It should not be operated at too
• great a distance or with children or pets too near.
  
• Don't let children play with the transmitter.
  
• Don't - operate door continuously or let door deliberately hit an- obstruction.
  
• Do - change the battery periodically (usually every 6 months or earlier).
  
• Do - read and follow the maker's instructions.
  
• Do - expect range of operation to vary with different locations and conditions,
• even different weather such as humidity.
  

Save a service call.
The owner can remedy common problems like those described below by referring to the manual supplied with the opener.

Door appears to have no power - check that power and master switch are on. Manual door lock may be locked or the motor leads may be loose.

Door operates faster one way than the other - may need spring tension adjustment or motor may not be correctly adjusted. Check and adjust as needed.

Door works from control but not from transmitter - replace battery if flat. If not, check if leads and switch need replacing. Also check that the coding key in control box matches. Both must be correctly fitted.

Transmitter range varies - although some variation is normal CB radio may be interfering, battery may need replacing or aerial needs re-positioning. An incorrect aerial may also account for door reverse being reduced beyond normal.