I work for a garage door company...I talk to people like you everyday.
For starters no one in their right mind would sell you a tortion spring. It IS very dangerous!!! These spring have about 40 winds on them, and if youre still able to open your door then you must have a 2 spring set up, and the other one still has tension, to replace the broken spring you have to unwind the non broken spring(this is where you could lose a finger or limb)...some companies will come out and replace just one spring, this is not honest or ethical work, because once that non broken spring is unwound it loses 60% of its strength(and the guy who winds that back up is abig ol idiot because it could burst sending shrapnel flying). Like I said the honest and ethical way is to replace both springs at the same time, this will properly balance the door, helping the door go up evenly and smoothly. If possible shop around and find out if the company sells "high cycle" torsion springs, commonly refered to as 30,000 cycle springs, cycle meaning the ammount of times you can open and close your door...most companies sell only low cycle 3000 springs, a 3k spring will only last about 3-5 years(great if youre selling the house, crappy if you just moved in)you may pay 15-20 bucks more per spring, but it is well worth it and you will know the co. that youre dealing cares about what they sell and is usually a good indication of the co's reputation.
But be careful opening and closing the door, in fact I would discontinue using it until you can get a company out there, if youve used the opener since, chances are youve striped the plastic gear inside the motor(cheap easy fix bout 79 bucks if its a brand still manufactured). A door unsprung is very heavy it would probably take 2 or 3 guys to lift it, you probably can, but coming back down is where problems arrise, the door could go crooked or worse yet fall out of the hole! Leave it be! The more you mess with it the worse it can get. Its a simple machine that uaually gets the best of the most handy, leave it to the pros.
Just a recommendation, I wouldnt use the Overhead Door Company...its a national franchise, which sounds great, but if you put one of thier openers in there, you are stuck dealing with them forever until you replace it...and you are at thier mercy, they get there when they can, and they know you cant get thier product anywhere else...when purchasing an opner(if need be) go with Liftmaster or Sears/Craftsman or Chamberline...its all the same company, and anybody(company) can fix it. Also Genie is a good name.
One last thing Garage door companies and people are shady, I dont trust very many technicians...they are all salesmen...just be careful, go with a large company if you can, that way in the future when you need service or warranty related repairs, they will hopefully still be in business, its very common for door companies to go out of business after a year or 2.
Hope some of this helps, if you have any more questions I'll be happy to answer.
