My automatic garage door opens, but stops after about 4 inches.?
There are tension adjustment knobs usually located under the plastic dome on the head unit attached to the ceiling of the garage. When the temp changes or the chain needs oiling, sometimes you have to adjust them. But first get some good silicone/synthetic Mobil 1 lubricating grease (auto centers sell it) and lubricate the chain, sometimes that's all it needs.
Stay away from the motor the problem is with the opener there are two screws on the side or back of the unit one will say up the other down with a screwdriver turn the up screw to the point that the rod just begins to bend then back it off ever so slightly.
It shouldn't stop while going up. If it syops while coming down, tighten the adjusting knob on the rear of the motor unit. Only tighten it enough that the door does not stop. This is a safety feature that makes the door reverse if it encounters an object on it's way down.
From experience I can tell you there is one of two problems. First, something could be blocking the track or door and not allowing it to open. Second, you could have a broken spring. The springs are tensioned to balance the weight of the door against the power of the opener. If a spring is broken the opener won't be able to handle the weight of the entire door. Good luck.
JimS is correct. With the door closed, disconnect the opener arm from the door (there should be a release cord). Try opening the door by hand. If unable to, or the door is difficult to open, then the door itself needs servicing. This may include a broken spring or a bad torsion bearing. I would highly recommend having a professional repair the door. If the door opens and closes without a problem, then the opener itself needs adjustment. You can try gradually increasing the open force setting until the door opens without a problem.
