ideal mexico cf 3/70 super problem!

[kingprawn72]

got a problem with an ideal mexico super boiler!
i drained it down today to and put fernox in one radiator.
i aired all the rads and made sure they had refilled
i refilled the system and i have hot water but no central heating!
the boiler won't fire up when i adjust the thermostat but about half an hour ago the boiler had fired up and when i adjusted the thermostat the boiler went back to just the pilot light!
the pump is working but doesn't seem to be circulating the central heating water!
any help would be greatly appreciated

 

[kevplumb]

bleed the pump

if you have a three port valve it should be locked mid pos when filling

is there a vent near the cylinder

 

[kingprawn72]

bleed the pump

if you have a three port valve it should be locked mid pos when filling

is there a vent near the cylinder

three port what!
i'm a spark mate
how do i bleed the pump?
the pumps working (very hot) but the pipes connected to it are cold!
can't see a vent.
there are two pipes from the pump going into the back of the boiler
each pipe has an on/off valve!

 

[kingprawn72]

the boiler has a myson compact external pump at the back of it. both pipes attached to the pump go into the back of the boiler!
any help please

 

[kevplumb]

undo the black plastic nut in the middle