Question: I have the opportunity to purchase a Vigilant Model stove, however, my concern is that the stove is a coal stove and I want to burn wood. How long ago did this style stove change to coal burning? How do you differentiate between coal/wood stoves? How can I determine whether this stove is a coal stove or a wood burning stove? Is there a serial number to check to get the stoves age and model? Any help would be greatly appreciated. Answer: I'm happy to help. The Vigilant wood burning stove began in 1977. In the early 1980's, a retrofit coal kit was developed. In 1985, the Vigilant Multi-Fuel Stove was introduced, which was the genesis of the current coal stove. This stove was outfitted with a series of reciprocating grates to hold the fuel, as opposed to building a fire directly on the bottom plate as the wood burning model. In 1986, EPA emissions regulations began to sweep the country and the Vigilant wood burning stove was no longer able to be sold as a wood burner in our country. Because of regulations, the Vigilant Multi-Fuel Stove was changed to the Vigilant Coal Stove. The Vigilant Coal stove can burn wood as a primary fuel. However, without the use of a combustor or a specific non-catalytic combustion design, the efficiency will not be terrific. I would estimate it's overall efficiency to be in the high 50's / low 60%. Burning wood would not damage the stove. Another factor is the firebox-------the elevated grate reduces the amount of fuel you can add so an overnight burn is a question. And the grate system with it's underfire air design for coal burning purposes may also play a role in a shorter burn time. If the ash pan is accessed through the front doors, then it was built before 1992. If the ash pan has a separate dedicated access door, then it is a post-1992 model.