Hi There OilHead. My mother in law lives near Knighton in Shropshire. She has a Kidd VHE model 1 oil fired boiler. (a large one). It has been serviced recently and since the service the boiler fumes can now be smelt when it is on (not on the inside of the house but outside from the flue) The flue fumes are now dirtier than they were before. Can you help please. Many thanks