I am looking into installing a cooker hood to put above a gas cooker, however, we have just purchased a combi condensing boiler for the kitchen with a horizontal flue to get rid of fumes externally. After looking online it would appear that due to UK regulations this means we can not have our cooker hood ducted due to having a boiler in the same room? Is this correct? The information I have read says that this is only possible when you have a balanced flue, but I'm not sure what this is......