worcester 35CDi II boiler

[widbaz]

Please can anyone help me.

Having just replaced 2 radiators after draining the system, my boiler now seems to have an air lock in it.
I have bled all the radiators in the house and they are free from air.
Everytime I try to reset the boiler the pump runs and the gas ignites and after approx 30 seconds there is a judder within the boiler and it shuts down.

The manual supplied with the boiler, which I inherited when I purchased the property last year, has no trouble shooting information.

 

[jasongates]

Maybe the Auto air vent within the boiler isn't operating.
or
Do the heating pipes from the boiler go up into a roofspace, if so you may need to check air vents up there.

Does the boiler operate in hot water mode?

 

[Andygasman2010]

There's an auto aire vent on top of it. make sure the black dust cap is loose, if it is you may need a new one. It's inside the combustion chamber so you'd need an RGI