Why the Hall Effect sensor is half lit or flickering on a Baxi 600 or 800 boiler 

If you can't figure that out you should not be a fitting boilers

I have a Baxi 630, its a beautiful design.

Where can I get the turbine switch as my hall sensor is red. Or what's the part number for baxi duotec 2 ba 40

If the boilers not registering a dhw demand boiler wont fire so cant feel pipework? Wouldnt turning the cold off and running hot tap do same?

Hello Richard. Could you please ACTUALLY demonstrate how to set the self calibration function on the Duo Tec 2 GA range. Read the instructions, but simply doesn't want to do it ? Much appreciated.