Blocked Cold Feed Pipe

I have a gravity fed system. I have drained my system via the two drain cocks on the outside of my property. On trying to refill my system I noticed that no water was entering my radiators. It appears that the cold feed pipe leading out of my F&E tank is blocked as no water is leaving the F&E tank and entering the system. The reason I emptied the system in the first place was to add sludge remover as my radiators are only hot at the top. I am now without heating or hot water and as my family and I are in the vulnerable category, it is not likely that we would be having anyone visit the property during the coronavirus pandemic. I am hoping that there may be some tips/tricks that I can try myself? Many Thanks