Does the motor run it back down, or does the door slip and then the motor kicks back on and pulls the door back up?? Be a little more specific and check the door balance. Disconnect the door from the opener in the down position and raise it up. See if it feels heavy and see if stays in the up position on it's own. You may have a broken spring or springs need to be adjusted.

Thanks for your response regarding the motor no it does not run the door down after the door slips a foot or two the motor kicks in and pulls the door back up and then it stays open in that position. I can't understand why the door slips down to begin with as ot is practilly in the level position after it is opened. There is hardly any downward force to make it start closing again,
Again thanks for the response maybe I should replace the springs if you believe that may be the cause any other input you may have I would be glad to hear
Regards John

Something is dreadfully wrong with your door. If you don't have it looked at soon you will also be replacing your opener. Is your opener 2 years old or is it an older model that you installed 2 years ago? You really need a technician to look into this.

Again, check the balance of the door manually. Close it, disconnect the operator and raise it up. See if it stays up on it's own. Otherwise, I agree that a technician may need to come out and take a look.

Thanks guys for your response I think will call a technican regarding the opener no it is not more than 2 years old . I installed it new andit worked fine. Maybe it is already starting to wear out if it has work harder if the door is not balanced properly.
Thank again I really appreiacate your help
Regards John