Had my Enviro MIlan for about 6 years now and for the past month or so it's been shutting off and not staying lit. At times it will run for days, and other times for hours and it just shuts off. Most of the time the burn pot is full of pellets when I notice that it's out. The stove is flashing a #3 error code which seems to mean that 'no proof of fire detected" by exhaust temperature sensor due to igniter failure, empty hopper (this isn't the case) or faulty temperature sensor. I've read the manuals and googles for hours and can't find anything on how to check these things. I have given the stove a deep clean and disconnected and connected all connections and now it wont stay on at all. It goes out within minutes. I have noticed that it seems like when this has been happening the pellets on the right side of the burn pot don't burn, it's as if they're not getting enough air. I've tried giving it more air but that doesn't seem to help. It seems like the pellets don't burn so the flame gets mothered by other pellets falling into the pot. It seems to stay on longer (and not have an issue) when the temp is set on setting 4 instead of 3. The only other thing I've noticed is the door gasket could stand to be replaced. I've also connected and disconnected the air intake tube. The both fans seems to be working, the convection blower is hot to the touch but this may be normal and it feels like it's spinning, The combustion blower I can see spinning. I am not on a thermostat. I guess this is a long way of asking - how do I check to see if the sensors mentioned are faulty? Thanks!