I have a Harman XXV which I have put about 4 tons of pellets through over the last 2 years. Recently the stove stopped working in the middle of the night and a quick bit of troubleshooting the next morning revealed that the problem was that the auger was not turning at all. I removed the rear cover panel to have a look and the chain that links the auger motor to the auger itself had come completely off the gears. I removed all the pellets from the hopper and fed whatever pellets where left through the auger by manually turning the auger gear with my hand. The auger seemed to spin freely and the push plate seemed to engage without any restriction. So I put the chain back on and adjusted the tension and refilled the hopper with pellets. The stove ran perfectly for a few hours, but then started making this periodic clunk/bang sound. It would happen every few minutes. So I removed the rear cover panel again and sat there and watched the auger motor, chain, and push plate until it made the banging sound again. The bang occurs because the push plate appears to get "stuck" momentarily, which builds up a lot of pressure on the motor/chain, until the the push plate "unsticks" and all the pressure is released and the whole auger motor assembly goes "bang". Feeding then continues normally and silently for another few minutes until it does it again. What would cause this? The push plate "pushes" once per auger revolution when a cam type mechanism pushes on a fork that is attached to the push plate. Usually the push plate pushes without any binding, but every once in a while it seems to get stuck until enough pressure is built up and it releases all at once, producing a clunk/bang sound. The sound is loud and causes the whole stove to shudder-- it's definitely not normal. When I had cleaned out the hopper after the chain fell off, the auger spun freely and the push plate never got hung up. It was only after I refilled with pellets and ran the stove again that it started happening. And it ran for several hours before the problem started. I think something is out of place in the push plate, but I can't see in there. What do you think? How hard is it to remove the push plate mechanism? TIA for any advice!