no flow from combi boiler to radiators?

Baxi Genesis 80 - hot water ok but all radiators cold.

When CH is switched on, the system fires up and the temperature lights indicate that the system is heating according to the control setting. All radiators have been bled. Pump has also been bled and checked by opening the centre screw and inserting a small screwdriver, which rattled around with the turning of the pump. Also, auto bleed valve opened shortly to ensure no air present. All seems ok, but CH flow pipe is cold, like the radiators.

What does the 3 way valve do? Could this be the cause of the lack of flow?

Any ideas?

HandyAndy
September 2005