Having a hard time trouble shooting a Summers Heat 55 SHP22 (englander 25 PDV). Not getting any error codes. Starts up fine, burns for awhile then the top auger stops it's intermittent turning cycle then shuts down due to no pellet feeding. Vacuum switch hose was cracked so I trimmed it back, blew out line going into combustion fan chamber, tested vacuum switch, seems fine, by passed hopper lid safety switch and still haven't resolved the issue. What am I missing here. Replaced combustion blower about 2 weeks ago was working fine. Sometimes the auger will start feeding pellets again before it completely dies out. TIA