Warmflow oil combi boiler issue

[villiers1041]

So
Gotta kc70hee warmflow combi oil boiler and was fine.
Now the burner is not working and light in panel, burner light.
So i changed the burner to a KNOWN working one off my sons boiler and still the same, swapped my burner to his boiler and is fine, so i think boiler is the issue.
It has the eco switch that if i turn off burner fail light goes off but no firing.
And no 240 to the burner at all whatever switches i press.

Any ideas please
Many thanks.

 

[Exedon]

Low system pressure?
High limit stat? First things to check.

 

[villiers1041]

Tried

 

[villiers1041]

Changed all stats, got a spare boiler panel here you see
And tried new p c b
No different

 

[Exedon]

If you have a multimeter and are competent to work with mains voltage just go through the falt finding sequence in the manual.

 

[villiers1041]

Yes
I am a mechanical engineer
I am doing process of elimination now

 

[villiers1041]

Sorted
Was indeed the limit stat
Cheers for the help