If the pump were not working the heated water would not be moving away from the heat exchanger quickly enough - or at all - the overheat safety thermostat would trip.
Turn off all your reads except one or two. Set the boiler thremostat to its mid position (3 on my boiler) set the room thermostat to maximum and turn off the hotwater at the timer programmer - see what happens.
You can increase the heat of the pumped water with the boiler thermostat - but not too high. You can speed up the speed of the pump - they have a speed adjuster (well mine does). You can balance the radiators so that the available heated water is properly shared amongst all the radiators and not being used up by the first few.
If any radiator is hot at the bottom but cold at the top then it will need bleeding.
If your rads are still cold after this then call in a specialist.
