Check the IRS website
It is possible to get a credit for installing an efficient boiler / furnace, as well as other energy reducing measures. (ie Insulation, windows etc)
However the credit is not large. I maxed out on windows and doors last year and got a $200 credit. Worth filling out the paperwork I guess.
There are very specific requirements for boiler & hot air furnaces. Just because they are new doesn't mean they meet the efficiency guidelines. I researched a little last year. To be honest I really don't think a wood fired boiler will get close to the necessary efficiency standards.
There are forms and regs you can download from the IRS website. Also contact the manufacturer or retailer. If it qualifies that's a big selling point, they'll surely know.
Keep us posted.
Take Care