Bottom ring not reaching temperature in Equipment Use and Repair Posted April 11 · Report reply Replaced the switch and the problem persisted. Fixed it by gluing one inch of refractory blanket to the outside of the kiln bottom. I also have a firing schedule where the bottom is always turned up more than the middle. I also put a final shelf between the last pots and the lid. I end with the bottom of. High, the middle on 5.5 and the top on 6. Cone 6 everywhere now!