In message , the swede
writes

I have a gas heater in my greenhouse which is 8 feet by 6 feet with high
eaves. However, I do get a draught which is coming from the door. My
greenhouse is pretty new and I do not feel like buying a new one. Can
anybody advise as to what I can do to stop the draught, I have tried to
adjust the door but it is not very easy.


You need a draught, or rather you need a supply of air and someway of
getting rid of the combustion products
--
Chris French