ML850. Setting the Limits

[Doorman]

I have installed an ML850 on a client's cantilever garage (Type A in the manual). Having read the instructions numerous times and gone through the automatic set limits and manual set limits I am at a loss as to why it won't work.

I open the light cover compartment, press the black button until the yellow light blinks slowly, then I use the black button to open the door up to the position I require, then I use the remote key (or the hard wired pad) to set the limit.

According to the instructions the door should then close and open up to the set position. But all it does is flash once when remote key is pressed then 5 secs later flashes 11 times.

When the door is closed, the remote key or the wired pad will open the door smoothly, but will run the door against the doors physical stops then shut off. Another press of the remote only makes the unit try to open the door further, but shuts off on force limit.

Your help with this matter would be much appreciated.

I had the same problem and response from Liftmaster was to install the Protector photocells, (as advised in the installation guidance!)

I've now done this and the opener, and setting limits is working perfectly.

Doorman