I have a Weil McLain (Gold Oil) furnace. It's about 7 years old. There is a blinking green light on the furnace and of course the furnace won't work. We've been smelling oil exhaust for some time, and last night it stopped working. We reset it, then started again, but now the light is bliking. Does it need a tune up? I've been reading about it on the internet, but I'm not sure that's what it is. Do I need to add that we never had this furnace serviced? Perhaps that's the problem. Thank you.