I thought it was just me!!!! apparently not, promax 24/2 fitted & commissioned dec 2008... same problem
power flushed system twice, upgraded to 15/60 grundfoss pump, pressurised system, running out of places to fit auto air valves, upgraded to 22mm pipe all the way back to gas meter,........wish I could have my old Prima back, begining to wonder if this is an inherant fault with this boiler, must contact pottertons
Mick (pulling his hair out ) Baker, January 2009