My pellet stove will start up perfect, run for a hour and then shut off . There’s two new thermostats on her , auger motors are working good , new blower motor. When she shuts down I press the power button again and she goes perfect again for a hour. I’ve cleaned her out regularly, even blowed out the front with a air compressor. What else could it be ? Am I missing a step in the cleaning process or what? Any help would be greatly appreciated