Liftmaster 3255 not fully opening.

[Jeff T]

Came home from a week long trip and our 20 year old Liftmaster 3255 would not open very far. Door would open about 12" and then close. Did some digging and old sensors came up as a common problem. In the mean time I disconnected the door from the trolly and everything worked fine, up/down no problem.

I replaced the sensors, no change. Back to the interweb and another frequent failure point is the RPM Sensor. Bought that, installed, again no change.

With the sensors connected to the opener, it will go up a little and close. With the sensors disconnected I can repeatedly press the wall button to get the door to open. To close I need to hold the wall button all the way down. Any thoughts?? Thank You.

[TinyTool]

Hi! Welcome to the forum!

It sounds like you’ve already tried a lot with your LiftMaster 3255. Here’s what I’ve found that might help. When a door only opens about a foot and then closes, it’s often something like the travel limits, the force setting, or the sensors not reading right.

One thing to try is pulling the red release cord and lifting the door by hand. It should move fairly smoothly and stay about halfway open if you let go. If it feels really heavy or sticks, that could make the opener stop early because it thinks the door is hitting something.

If the door moves okay, check the little screws on the opener that adjust how far it goes up and down. Turning the “up travel” screw a little might let the door open more. You could also try slightly increasing the “up force” if it keeps stopping too soon.

Also take a look at the sensors. Both lights should be solid when aligned, usually green on the receiving sensor and amber or yellow on the sending sensor. Make sure they’re aimed at each other and the wires are connected. Since it works better when the sensors are unplugged, it could be a wiring thing or the opener not reading the signal right. When the sensors are unplugged, it goes into a safety mode, so you have to hold the wall button to close. That’s normal.

If none of this works, it could be the logic board inside the opener starting to fail.

[Jeff T]

One thing to try is pulling the red release cord and lifting the door by hand. It should move fairly smoothly and stay about halfway open if you let go. If it feels really heavy or sticks, that could make the opener stop early because it thinks the door is hitting something.

Disconnected the trolley, can't lift the door. It has a Wayne Dalton Torguemaster instead of the standard exposed springs that I'm more familiar with. Time to call a Service...

[davidlaid]

sounds frustrating after coming home from a trip! Since the door only works properly with the sensors disconnected, it really points to a sensor alignment or wiring issue. Even new sensors won’t work if the wires are damaged or the beam isn’t lined up perfectly. I’d double-check the wiring near the opener and make sure both LEDs are solid. That usually fixes this exact problem.

[Jeff T]

Since the door only works properly with the sensors disconnected.

With the sensor wires disconnected, the button has to be pushed multiple times to get the door to open. Conversely, it has to be held the entire time it's closing.

As I mentioned, with the trolley disconnected I cannot lift the door. That's why I'm thinking it's the spring or springs since Wayne Dalton doors have internal springs.

[TinyTool]

Ah, I see! Since those are internal spring systems, it makes sense to call a service tech. If you can't lift the door by hand with the trolley disconnected, that usually points to a problem with the Torquemaster spring system. When the door is that heavy, the opener will struggle and shut itself down because it thinks something is blocking the door. That would explain why it only moves a little before reversing.