They are but they need to be an 'Eco Design'. There are also rules about the wood that is able to be sold, a lower moisture content.Are log burners still allowed to be installed?
https://www.rnwilliams.co.uk/uncategorized/are-wood-burning-stoves-going-to-be-banned/ This is an installer but what they have put is repeated on a number of other sites so it seems to be accurate