My toilet is plugged. I'm trying to use a plunger to unplug it. I turned the water off to the tank. I'm not sure how far it was turned when it was open originally. If I flush it and it's not opened properly, will this cause a problem? Does it have to be opened when it flushes? If its still plugged, how to I keep it from flooding.

Thanks,
A.M.

If I flush it and it's not opened properly, will this cause a problem?
No. The valve should be open all the way. However, if it is not open at least about 1/2 way it will probably cause the tank to fill slowly. That in it self is not necessarily a problem unless you wish to flush the toilet twice in a short period. How far open the valve is has nothing to do with the flushing.

If you wish to make sure that the toilet is no longer blocked and not want to risk overflowing, pour water in the bowl using a bucket. That way you can stop pouring if the water does not drain.

From your post I'm not really sure, that your toilet is still plugged. But if that is open up the valve to the tank and leave it. Now purchase a closet auger and auger out the bowl. Good luck, Tom