Moderator Post (s) for this thread: >Preway stovesbytomh on 11/16/2004
I am not familiar with the pre-way. The differences between LP and Natural gas systems is the orifice. LP's are smaller. You should look for the number on the orifice and check with preway's site for your model's requirements.
Vent free gas systems are controversial and not allowed in all jurisdictions. You would be wise to ask pre-way and also check with your jurisdiction for their use. Usually triple wall is only for wood burning systems.