By switch do you mean wall button or remote? Does it work fine from one and not the other??

By switch, I mean the wall button. It will only open with the remote if the weather is above 30 degrees. And, to get it to open with the switch in this cold weather, we have to fiddle and fiddle with it.

It sounds to me like you have a circuit board issue. If the opener is not really old I would put a circuit board in it and see what happens.

My door suddenly stopped opening up when it got really cold last week. I too had to "fiddle" with the swith to get it to open. I assumed it was due to the cold weather causing some resistance. I simply adjusted the Up force adjustment knob to give it a little more force and it now opens fine. Not sure if your door opener has a force adjustment knob or not, but likely it does. I'd try that and see if it makes a difference.