central heating nightmare

hi i hope u can help at the weekend i had to install a new pump as the centrol heating system failed . after installing i refilled the system but only the top rads were working even after bleeding ,so i emptied and refilled as i thought that it might be a air block but after refilling again i still have no heating on the ground floor .
please help

One possibility is that the pump isn't the right size; too small for the load you are putting on it.

Another possibility is that the main level has a blockage.

You probably need to bleed all radiators, starting with lowest to the top.