I used to install and service quadrafire pellet stoves. Im not familiar with your model but most pellet stoves have heat exchanger tubes that blow the hot air into the room. Generally these are at the top of your combustion chamber.
Ash will build up around these tubes and actually insulate them preventing the steel from heating up to an efficient level. Removing all the baffels within the firebox and cleaning the ash from around these tubes
should provide an immediate difference in the amount of heat you get.