Rounded screw on plate heat on a baxi duo tec

[Jonny wall]

Has anyone come across a rounded screw on a plate heat exchanger on a baxi duo tec and not been able to get it out?
How did you overcome this on what is essentially an easy job. If possible I don’t want to have to take the whole manifold out on the right

 

[ShaunCorbs]

Drill the head of the screw off

 

[Last Plumber]

As above, drill it out and use an extractor if the head is accessible.