Ideal logic vs independant?

[Nostrum]

What the difference between these 2 models? Looking in the Williams catalogue there's about £50 difference, yet the warranty is (currently) the same, so what's inside the box of one, but not the other?

Cheers in advance

 

[Ermintrude]

Case different, hydra block plastic in cheaper one. Think text display is same as logic not logic plus. No integral filling loop.

 

[Scott_D]

No pre made bends or Prev termination kit with the independant
Independant come with free flue and clock