glow work swiftflow 75/80/100?

I have no hot water or CH. Problem started after removing a radiator to decorate a spare room. Low pressure light is flashing although 1.5 bar ATM. Fan is running, I bypassed flow switch and that seems to work. Any ideas? I have tried bleeding the pipes for the removed rad and another rad in a different room. The boiler doesn't fire when the taps are turned on but sounds like it does when CH switched on. However, no heat in rads when left on for 30 mins.
Help?????!