Yea, make sure you have ENOUGH coal. Meaning more than the 7 mentioned in the guide. Just take as much as you can. I'd say turn the valves both half open, then just put some coal into. It takes a while so don't throw in all your coal if you don't see progress any soon. Make sure the heat and pressure don't go paste the red section, but if you see the heat is dropping put in some more coal to get it up again.