I've reset the damn code twice. Works good for a few days then poof I find the damn thing open again. No ryme or reason for it. Any ideas before I take a bat to it?  It's currently set to lock.

ETA it's about 1.5 years old.

By "code" do you mean frequency? If not then reset the frequency too. Someone else may be using the same one or playing with you.

Yes I meant freq. there are new builds nearby so we figured it was that.  Now IDK wtf is going on with it.

Unhook your radio receiver from the operator.  If the gate operator stops opening on its own, then you have your answer.  If it keeps it up, then next try your keypad, or whatever other access device you have.  Keep doing that till you find the problem or have tried all the devices.
If none of the access devices are causing it, then it is time to see if wind or some other force is working on the gate causing small movements in the sensors that the circuit board reads and reacts to.

Ok I'll give that a shot ty.

Whoops, I thought a 8165 was a gate operator, I googled it just now because I didn't recognize the model number and it is a garage door opener. 

Fortunately the above steps apply to both the same.

One thing I have seen relating to the radio receiver and transmitters (transmitters are what we all call the little garage door openers we put in our cars, or on our keychains) is that sometimes a transmitter somewhere in the house goes a little crazy and starts going off on its own without the button being pushed.  If you have any garage door openers that are in a drawer somewhere or in a spare car or something, try taking the battery out of them.  Or it even could be one of the ones you use every day.  It is a tough one to troubleshoot, it just takes time trying everything for a few days.

Yea I removed the batteries to the extra remote. I thought it might be the wife's car with the built in opener but nope. Could battery drain cause this? I'll unhook the transmitter this weekend and give it a go.

Thanks for the help

Until you figure it out if it's wifi capable you can get an app to let you know when it opens, also can do on website with PC.

Yes.  When you use it the voltage may take a while to return to what it needs to be and that can cause weird stuff. 

Radio controls are just weird period.  I have seen them work for over 1000' in some places, and the exact same equipment won't go over 20' in others. 
My theory is that all the signals being beamed from here to there for weather and traffic may be causing some of it.

Hmm ok gonna do some testing! Thanks for the help!

My previous house had an issue where the opener would open on it's own. I went w/ it being the change in temperature and some component was changing value.

When it would happen I would change the sensitivity settings on the unit.

Never got bad enough to investigate further or swap it out.

I'm gonna leave transmitter unplugged for a week and see if that fixes the issue. If so then I'll see if the wires are loose.

Check your safety beams, sometimes they get out of alignment and intermittently reverse the door while closing.