SUPRIMA60 + BOIlermate 2 no water

hi my mate fitted a new primary heat exchanger to his potterton suprima 60 he didnt know where the shut off was so opened valve on his boilermate 2 and on the suprima60 and drained drained the system . cut to the chase he fitted exchanger switched all taps on closed shut off valves he has water to taps bath etc but no water to the heater fires up ok but no water flowing through he opened up the drain tap on the boilermate 2 and it seems to not have any water in the tank what has he done wrong any help please p.s both pumps spinning

I would suggest he turns off the boiler rather rapidly unless he want to fork out for another heat exchanger. I suspect the internal cold feed in the boiler mate is blocked............In the past i have cut into the header tank and used a 22mm tank connector and fedd the cold feed externally to the drain off connection on the cylinder.

I wonder how long hte pumps were spinning for??