Hi Terry,
No news on the CO front until Tuesday. Re Turbulators, sorry, don't know. Can only suggest you do what I did, and that is to search ebay for turbulator and then save the search. Once the search has been saved you will get an email if anyone puts anything on there. I bought 2 sets this way, but turned out they were listed under the wrong part number and were for a 155 and not a 140. My engineer spoke to Baxi and they said it would be OK to fit them.
Andy