Huknpuf, Steve is right. Bio in your heating system can cause problems. If you are prepare you can avoid them. I heated my 200 year old drafty house this last season with Bio. I did have to buy 50 gallons of dino due to short supply but I am pretty satisfied with my results.
Things to think about. Bio will eat the seals in your fuel pump. You need to get one with Viton seals. Patriot Supply sell a Webster model. I have 1 furnace and 1 boiler. I lost the pump in the boiler first and then about 2 month later I lost the pump in the furnace. I had Carlin burners with Sunted 2AV fuel pumps. The Webster pump a perfect replacement. If you are hand you should get the manual for your system at a local plumbing supply house. Furnaces look daunting but they are rather simple devices. The burner part needed more frequent cleaning than I thought. But after a few sessions I got pretty good at and fast. As I begain to get comfortable working on the system I found the right setting and the systems work great and burn cleaner.
The Bio also will free all of the junk in your fuel tank. You will need to get some extra filters and check them often. You may also end up with a clogged fuel line. You can either clean themor replace them.
Any way I burned just under 1500 gallons of Bio that I made. I figure I saved about 3,000 so far. This summer I hope to find an other supply so I don't run short.
Good luck
