I have a Vulcan V-50 pellet stove. When I start it up it goes through its normal cycle and the feed rate light goes from flashing red to solid red indicating it is up to the proper temperature and will now continue to run at the selected feed rate and fan speed. It will run for anywhere from 5mins to 10mins and will then go into shutdown mode. What's the deal and how do I fix it so it continues to run properly without prematurely shutting down? Please help!!!!!!!