I notice the stove seems to run pretty dirty when it is running a low flame to keep the set temp in "Room Temp" mode(in this case 75 - when its 45-50 outside), is there a way to force the stove to run hotter, then shut down? At night when its 30, the stove seems to run fine, but during the day it dirties up fast, today creosoting the Heat Exchanger.