Cooker extraction - can I use original ducting??

[damurphster]

I've just bought one of these.....

http://www.luxairhoods.com/index.pl?c=SSHOODBLACK

Max extraction is.... 'Capacity Max Setting (CBM/H) 550'

It specifies in the installation manual that I have to use 125mm ducting and not the original ducting or 100mm ducting or warranty is invalid.

My original ducting is 100mm and in between walls, potentially concreted in!

Whats the problem with me using the original ducting? Why the drama with 100mm ducting? I understand I will probably loose some extraction power but that is all I can think can go wrong?

Am I missing something? I have a feeling this is just a good way of Luxair 'getting out' of their 5 year warranty as I'm certain few people have the option of changing their ducting!

Any opinions?

 

[jj4091]

I agree with what you are saying, but they decide the rules of their warranty scheme, but I do not see anything in their requirements that says you have to have a 5" hole so fit a 5" ducting & then connect to your existing hole with one of the reducers shown at the bottom of this page : http://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/Ducting_Round_1/index.html