Restarting Vaillant boiler after extension

[becksbe]

Hi there,
Our Vaillant boiler has turned been off for 4 weeks due to an extension being built, a radiator has been moved and extension flu added (flu still isn't quite long enough so full ventilation is not currently present)

After restarting the boiler and refilling the rads the hot water and radiators would begin to get warm but then the boiler would cut out, and then start again a few mins later and do the same.

Could this be due to an airlock ? do I need to bleed all rads ?
Could the ventilation flu be effecting if ?

Any advice would be much appreciated.
Many thanks
Becks

[Steve the gas]

Hi Becks,

Yes all rads should be bled also pump etc.
But DO NOT use the boiler until the flue is finished correctly.This is the bit that can/does kill!!