We have 6-8 year old Marantec 4700e door openers. I think they are direct drive or belt driven. (The quiet ones...no chain.) The techs have been here multiple times to adjust the units. Since January, they have been out about 7-8 times. The unit that is used most often, continues to have problems. It sometimes jerks when I try to open it, and it only moves an inch or two, but does not open. Other times, it does not jerk at all, and does not open. Sometimes it opens fine, but when I try to close it, as soon as it hits the bottom, it goes right back up. I know that is probably the safety limiter. To keep it closed, we have to hold the button until it goes completely down and stops, then release the button. They replaced the 6-7 year old spring with a new enclosed style. Sometimes the cable wraps around the ends wrong, so we are not happy with the new spring.

The techs' answer is for us to buy new ones. We told them no. The next time they came out (17 miles) they replaced one of the units with Marantec Synergy 270 without my knowledge. I don't know if that is an equivalent unit or not. They charged me $200.00 for a trip charge (17 miles), and never said they had replaced my 4700e with a used Synergy 270. I noticed it was different the next day. They took my 4700e with them without permission. The only problem it had was the light would flash. We had to turn it off with the wall switch.

It is obvious, the techs don't know what to do, and the units are not that old, so I thought I would try to fix them ourselves. We are about an hour's drive to a medium size town that probably has a garage door company. The local company we purchased new doors and the openers from 6-7 years ago are the only company in our area.

My questions:

1. Are these units just a bad brand? I have never had Marantec openers before.

2. Should they have left my 4700e here? Is it normal for them to keep the old unit that was working fine except for the light? Now I have two mismatched units. The new one has only one light, not 2 lights.

3. Is there anything I can clean like the rails or eyes? Nothing is in the way. Is there anything I can do to reprogram the unit?

Thanks for your advice.