Garage door reverses just before closed

[jubilee]

10,000 cycles is what everyone was telling me, and what the articles say. Frankly I did not know they had torsion springs for consumer doors 45 years ago. Everything we saw 45 years ago was stretch springs on mostly plywood doors. Some roll up but the springs were all stretch style with the cable in them to prevent them from knocking a hole in the roof when they went off, or putting a big dent in a car door.

4 cycles a day x 365 days a year x 8 years = 11, 680 cycles. Mine were at about 15,000 cycles when they were replaced on GP.

I have stretch springs. Learn something everyday. Thanks for the heads up.

 

[SGKent]

I have stretch springs. Learn something everyday. Thanks for the heads up.

Especially with that age make sure that yours have safety cables in them. They can really hurt someone badly when they break if anyone is near. Before safety cables we used to find them outside the garage after they went thru the roof. A friend had one really damage a car door. With the safety wires they can't launch. Most everyone uses torsion springs today - they take up less room and don't launch.

 

[Redding]

I have a garage door that reverses just before it gets to the bottom. It gets about 2 inches from the bottom and reverses back up. It reverses probably 80-90% of the time and other times it goes to the bottom as it is supposed to.

It is a Liftmaster 8500 opener. I have double checked the door limits.

Garage door is about 5-6 years old. Professionally installed. I have 3 of the same doors with the 8500 openers. I called out the installer about 2 yrs ago for this problem and they said the springs needed adjustment. They adjusted the springs and the door actually worked for some time. I am guessing on dates, but a number of months after they adjusted the springs it started having the same problem again.

I recall the service guy said that the springs need regular adjustment or this will happen. The other two doors, installed on the same date, have never been adjusted and work perfect.

I am skeptical that this is a spring issue, but I am far from an expert.

I will add that if I pull / force the door downward as it nears the bottom it will go to the bottom and not reverse.

This is likely a force issue, connected to the door mechanics itself. Its been 5 years since I put in doors professionaly, but there are multiple issues that can cause this.

Watch if the door is tracking hard to one side. Could be stuck roller or bent hinge causing the roller to stick.

Outside weatherstripping could be too tight at the bottom of the door on the sides.

Top section could be rubbing tight against the header as its closing. Top brackets can be adjusted to fix that.

Also, some information on your openers.

If these are normal residential doors with 15 inch radius track, where the curve and the vertical track meet just below the top roller, then the 8500 is the wrong opener for the door.

Jackshaft openers, where they are connected to the spring shaft, are and still only designed for doors with high lift. Because of ease of install, convenience, and aesthetics, companies install these openers on normal radius doors. This always leads to issues. All normal garage doors with normal radius track should have a railed opener attached to the ceiling that pushes the door, not rotate the shaft.

This was a sticking point for the company I worked for. We refused to use those openers on normal radius doors. Yeah, we lost some business because of it, but we never had callbacks because we put the correct openers in.

If the door has only one spring, that can be an issue with these openers as well.

Proper spring tension should be when the door is halfway up, and disconnected from opener, it should stay put. Not lower or raise, but stay put. But with these openers the doors needs to be heavy, othewise if it catches anywhere, the opener keeps turning the shaft and bounces the cables off the drums.

This directly effects the force needed to close the door. To compensate for this, and because Chamberlain knows companies are installing these openers improperly, they use a soft close near the bottom where the door slows down. Slower speed and restriction means less speed force to close at bottom, which causes it to reverse.

On springs, Life cycle on the average spring is 10,000 cycles. There isnt much that lessens that amount unless the installer doesnt stretch the spring enough before tightening the set screws. Unbalanced springs will still normally go 10,000 cycles unless extremely unbalanced to the door weight.

I always advised people who use their doors quite often to up their wire size on their springs to increase the life cycle to 25,000 or 50,000. Especially commercial shops with large doors. Little bit of a cost increase initially, but no replacement needed for a long time.

Most commercial rolling steel doors have a square wire spring inside their barrels and have a life cycle of somewhere between 100,000 to 200,00. This is because to replace these spring requires taking the door out completely, disconnecting the curtain from the barrel and sending away for repair.

But again, likely issue is restriction near the bottom of the door itself when closing.

 

[superduty1]

Not restriction as i mentioned earlier.

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[Redding]

Not restriction as i mentioned earlier.

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Have you lost power for an extended period of time? When the backup battery in these openers fail, the programming can disappear as well. Your wall control can have a scrolling fault just under the time if the battery fails. Unplug the opener and see if it will open or close.

The 8500 does not have physical limit switches such as most common rail openers. Its electronicly programmed along with the force adjustments. If it loses power for long enough the memory goes too.

Have you tried to reprogram the limits and force?

Also, the cable tension switch might be activating. The cable gets closer to the wall as the door comes down, closing the gap on the switch and stopping the door.

If you stop the door after lifting a foot from the ground, and push in the switch and see how close it is to engaging. If you barely have to touch it to hear it click, then maybe move it up a few inches on the wall or the wooden jamb.

 

[superduty1]

Folks, please read the posts above before you comment.... Unless of course you simply enjoy "hearing yourself talk", sharing your knowledge, or lack thereof, and don't really care about the actual issues.

Specifically, see posts 11, 17, 19.

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[Darryl2]

Fair enough, but have you checked the error code on the wall remote to verify that it is a sensor obstruction? Never saw that you ever mentioned what error code you got? Just that you saw a protruding handle, pushed on it and it seemed to help. Is the sensor light flickering when the handle passes through that region? Does the wall remote state that there is an obstruction? Move handle, re-align sensor, replace damaged panel.....

Trying to help. I have an 8500W and the few issues I had when first setting up were clearly called out on the wall remote.

 

[superduty1]

Fair enough, but have you checked the error code on the wall remote to verify that it is a sensor obstruction? Never saw that you ever mentioned what error code you got? Just that you saw a protruding handle, pushed on it and it seemed to help. Is the sensor light flickering when the handle passes through that region? Does the wall remote state that there is an obstruction? Move handle, re-align sensor, replace damaged panel.....

Trying to help. I have an 8500W and the few issues I had when first setting up were clearly called out on the wall remote.

I was unaware of the ability to check error codes on the wall remote. Thank you for that info. I will have to look and see what the last error was.

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[Darryl2]

Im not sure that it stores a history of the errors but if the error is active or just occurred it spells it out on the remote. I think there is even a blinking LED on the opener itself that translates to errors in the manual if you don't happen to have the LCD wall panel that scrolls the error.

I am out of town and going from memory.