Should I complain about my neighbours new chimney?

We've just moved in and our neighbours extension has a wood fired chimney which spews smoke into our garden (didn't realise this before we bought it) it is only 4 metres tall on our side of the garden literally about ten cm from our boundary. We live in a smokeless zone and our houses are Victorian and three storeys high. We haven't spoken to them yet but I need to build up a defence and good argument before I approach them. They must know it is an issue.