I have an empress insert for about a year now.past couple days,upon startup,stove lights,gets close to completing start up & turn on convection fan,and then pellets stop dropping.auger light stops as well.something is telling stove to shutdown.completely shuts down from here and #3 light blinks.I shut off stove & restart,and it runs fine..so far I completely cleaned stove,checked exhaust fan,proved exhaust sensor works.all wire connections look to be fine,vacuum line intact.please advise..