Am facing the problem of no water flow from the overhead water storage tank - although the ater tank is full. Is it to do with some air problem. There is also check bell attached to it.

Am facing the problem of no water flow from the overhead water storage tank - although the ater tank is full. is it to do with some air problem. there is also check bell attached to it. Is the water tank open or closed? If the tank's closed check the vent on top of the tank. If it's open let me know.
What's a "check bell" and what's it installed on?: Regards, Tom