Vaillant ecotec plus 938 not starting

drje

Hi i am in the uk got this new boiler i have connected to e bus directly from the tado thermostat and i have setup D07 but the boiler doesnt seem to be controlled and i can’t even start the heating manually ( only chemney sweep mode that heat up for 15mn and stop ) , hot water is fine obviously.
Any idea on what i should change ?
Thanks
Jerome