Been there done that. Replace the strong back gasket on the feeder or better yet all the gaskets and seal the back with furnace cement. The cement part is not in the manual, sort of belt and suspenders but it helps me sleep at night. Make sure the cement is smooth or coal will not flow. If you get air flowing back there the fire will burn too far back. When you moved the stove you probably removed the feeder or at least jostled it around a bit and now the gasket is not seated properly. The strong back gasket is the smallest, easies to damage and most expensive of all the gaskets. Also check the gasket on the coal bin and make sure it is not letting air in. Also do not let the bin get too empty. Another word of caution, my rheostat failed on Monday and my stove ran away because the stoker ran continuously. I caught the situation because the house temp went to 80 in a short time. I installed a Coal-Trol on Tuesday. I was luck enough to get a hold of them before they shipped for the day and it was here the following afternoon. It shuts down at 98 degrees which I wish was adjustable but at least it shuts down.
From the manual
Locate unit (See Fig. 1 on page 3 and Fig. 2 on page 2).
Check that strongback gasket is positioned properly as
shown in Fig 1. The strongback gasket position is critical
in that it prevents air escape to the hopper area which
could result in “hopper fire” or warpage to the overplate.
If you did not get one here it is http://www.produitsjl.com/pdf/kast_console.pdf