CH on Combi Boiler not firing up after changing rad. Help!!!

[jayzy1]

Hi, I've just had to install a new radiator (new position) so had to drain the system. This time I kept the flow & return valves open when I drained he system. Now after I filled the system back up and got the pressure back up the boiler won't fire up. (Worcester HiFlow 400 sealed system). Any ideas why?

Have I got air in the pump and would this stop the ch starting?
I also accidently let some air out of the expansion vessel inside the boiler, would that make any difference?
If so The manual says that the pressure in here should be 1/2 bar, Can I use a bike pump and how will I know the pressure is at the right setting?

Many Thanks for sugestions.

 

[ChrisR]

If you let much pressure out of the pressure vessel it'll need recharging - instruction in the FAQ section.

You DO need to bleed the pump on that boiler - remove the central screw, and you may also need to insert a screwdriver and spin the shaft within.

 

[weareleeds]

Also make sure auto air vent is open

 

[jayzy1]

thanks, actually it was ths the auto cut off switch that had cut in so i just had to press the button at the bottom of the control panen. silly me.