Hey All,

I moved into a home and tested the safety reversal of our Chamberlain 248730 garage door opener. It doesn't not work when a 2x4 is placed underneath.

I balanced the two torsion springs, adjusted the door arms a couple times, messed with the down travel and down force. The only time the safety reversal feature would work is if the down travel was moved a greater distance than reasonable. At this point, my door rail would bow upwards and it looked like a lot of stress on the garage door opener/rail. I returned the down travel to it's normal position of closure to avoid damage.

Any other ideas on what I could try to make the safety reversal system work correctly without having to bow the rail? Does anyone know what makes the safety reversal on a Chamberlain garage door opener function?

 

Does the door open and close easily by hand with the opener disconnected?

 

Pilot Dane, Yes, it does. I balanced the door beforehand and made sure it wouldn't move when it was at 1/4 down and 1/2 down.

At 3/4 down, almost completely closed, it does move. I tried tensioning the springs another quarter turn but then it makes it harder for the garage door to close when fully in the up position. (The springs held it up there pretty good unless I pulled down significantly harder) I settled for the prior by loosening a quarter of a turn on the tension springs.

 

In some cases the 2x4 test doesn't work if there is a lot of flex in the door or if the arm is too short and looks straight up and down when the door is closed.Try running the door down onto your shoulder to see how hard its pushing, decrease the down force if needed

 

Thanks for responding doorman.

I moved the door arm from being straight up and down to a bit more angled towards the opener itself (I moved it two bolts further away than previous) Here's a picture - should I try moving the arm even further towards the opener? (Please mind the foam next to the arm. It's out of the groove making it look like the door is bent inwards.)



Also, the downforce that's currently set is the lowest it can be set at or it wont close once open. When I hit the button it moves 6 inches before stopping and reversing.

I really appreciate everyone chiming in and helping!

 

Well, problem is solved. Talked to Chamberlain, and a door repairman, and I was told to put the 2x4 on it's side rather than lay flat. The door needs 2-3"s to actuate the reversal mode. And wa-la!

So, all is well with my unit. Hope this helps anyone else in the future. Thanks to all those who replied.

 

The arm looks good,but the Strut that is just below the arm should be at the top of the section. Like I said earlier the 2x4 test doesn't always work when there is a lot of flex in the door. Also the arm attachment bracket on you door is really meant for a wood door and the mullion its attached to will flex. If you really want this to reverse off of a 2x4 you will need to move the strut up and buy a better operator bracket, did you try letting the door hit your shoulder to see how hard it was pushing?

 

Good information, Doorman!

Can I reverse the strut with the current metal piece that's in it's location? Or should I leave the piece removed once the strut is in place?

I'll take a look at getting a new operator bracket for door.

I haven't tried with my shoulder but when I put my hands out, the door will reverse without pushing my arms down too much.

 

You can leave the other piece off when you move the strut up to the top of the section. Reversing with your hands is good enough. Ive never hears of reversing while using the 2x4 on it's edge, not sure on that if it's correct or not.