I turned off the water to the toilet to replace the flapper. After fixing the flapper I turned the handle to allow water to flow into the toilet and nothing happened. What has caused this?

Do you mean that you opened the stop valve under the toilet but get no water to the tank? Did you open the valve all the way? Is the float down?

As Harold says check if the angle valve is full open, if it is and no water, then it means something is wrong with the angle valve or the fill valve.

Do this first close the angle valve and disconnect the supply line at the at the bottom of the tank, place a pan under the valve and place the open end of the line in the pan, open the angle valve slowly and see if the water flows if it dose the angle valve is OK problem is with fill valve.

If no water with line disconnected, close the angle valve remove the packing nut, remove the stem check inside the valve if there is any debris, check the washer at the end of the stem if it is OK.

If there is water the problem is with you fill valve, see the images below and tell us which fill valve do you have and we will tell you what is the next step, Thanks.

John

Hello, sorry I've been trying to Google for toilet problems, but seems like the toilet I have looks like the model in diagram 400A. The water flow is so low coming out of the Link/Water Level Adjustment Cilp instead of the refill tube. The rubber tube coming out has a whit eclip connected to the overflow pipe instead of angle adapter or something. It happened suddenly, I tried adjusting the water flow on the wall but no results. So now I'm stuck with a really slow filling toilet. Was wondering if any of you can help before I call a plumber, thanks