Hello - had our first fire of the season last night and the blower on my Hampton HI300 wood burning insert was cycling on and off as the fire died out. I've had the insert for about 3 years, and have never cleaned the fan assembly. I'm assuming it needs some cleanup. Unfortunately, I cannot remove the assembly from the insert. I checked the manual and searched around online with no luck. It looks like it just slides under the main unit, but I can't get it to slide out. Is there a trick I'm missing?