Lowe's talks about a common toilet problem in this video tutorial about a slow-filling toilet. Most toilet tanks should refill within a three-minute timespan, depending upon the water pressure in your area. If it's taking longer than that, or if it isn't refilling at all, remedy the problem with these simple steps.
Joel and Courtney show what to look for if you have a slow filling toilet tank. First thing to check is if the water shut-off is completely open. If it is, look at the toilet fill valve. Sometimes there is buildup in the valve, so cleaning should help open it up. If the fill valve seems to be working fine, there might be a bigger plumbing issue at hand.