I would say that the installer has the chain too tight. If you have a gear-drive, then he has the guide track twisted. In either case, the result is an overload in the motor which causes the little heat-activated circuit breaker on the back of the unit to trip. Once it cools, the motor is back on and everything is okay.
I only know this from experience. I installed on myself, but it would jam intermittently. I finally had the Sears guy out. He loosened the chain, and tightened the door springs so the door would be lighter to the opener. I never had another problem.
Other possibilities: garage door binding in the tracks (did you also gust get a new garage door, too?)
If none of this works, get another unit. I think the warrantee is for a year. In case you were wondering, the openers are manufactured by Lift-Master.
BTW - I was reading everyoneís opinion(s) with this posting on this matter. Iím not looking to start a fight, but I think we need to keep in mind what type of consumer Sears is targeting. Their market share has declined with respect to the department store arena, but they virtually lead the industry in sales of tools and other hardware such as lawn equipment, and yes, even garage door openers.
I am sure those sales are not necessarily to professional carpenters or lawn maintenance folks, but thatís fine. Thatís not Searsí target audience. Professionals in the trades have demands that DIYers do not. Within their target, they are pretty much on top. Thatís why you see Sears stores opening up just for the hardware stuff. You donít get to be that big by selling inferior products. Most folks must be at least mildly pleased with what they buy from them.
My friends in the trade also, by in large, do not use Craftsman tools, but I do, albeit their top-of-the-line/industrial models. I build for fun, not a livelihood. Iím sure my saw would not last if I build a house a week, but I donít need it to. Even so, I probably use my tools much more than the average DIYer, and for me they work just fine. A little bit of maintenance is all it takes It is just is not cost-effective to spend the extra money for a tool that has a benefit level I most likely would not realize. I guess I am their target audience.
Well, maybe they are not as reliable, but at least they market under theyíre own name. Home Depot, for example, sells Dutch Boy paint, and Delta faucets under the Dutch boy and Delta names, but even though they are the same brand and model number, they have different UPCís.
And as far as lawnmowers are concerned, I have never bought one, though I do have a lawn. Iím mowing a lawn a week, not 10 a day. I simply fetch them out of the trash as neighbors throw them out. Usually in 15 minutes theyíre running fine. In 12 years only one was beyond a simple repair. Why spend the money when I know someone down the road will be "giving" me his in the Spring.