Hello, I have a Englander 25 epi pellet stove. It's been running fantastic for the last five years until last week. Whenever i turn it off, everything shuts down in exactly 5 mins. I timed it with a stop watch. This happens no matter what heat setting I'm at. I'm worried something is going burn up. I have to hit on and then off again to give it another 5 mins to cool down. It use to take 30 to 40 mins to cool down. I have changed the control board and thermal wire to the exhaust blower. I'm tired of spending money on this. Any ideas? Thanks!