thanks to you all for your help in finding the problem. It was the flue! Achoow! The previous owner used the plastic top of a shaving cream can...I believe it was reducing the airway for the exhaust. When I put the heater on test outside it fired up no problem ..when I put it back in either, the pilot would light but when the main jet tried to light it blew itself out. My theory is the pilot was burning/using the air in the exhaust type but when asked to light, it blew back and blew itself out...maybe?Anyway, once again, thanks to all for responding...what do they say in the UK?!? Every bit helps.......thanks again....ps. my feet are warm