Hi All, Thanks in advance for your help. I'm stymied. I purchased a used kiln and gave it a test run with a cone 5 in the kiln sitter and a cone 6 stand alone. It worked perfectly. It's an old manual kiln with a kiln sitter. 2 hours at low, 2 hours at medium, and about 2 hours at high before it switched off. Then, I added four reasonably small pieces that were glazed with 3 coats of c-11 celadon mixing clear. I used glaze from this container before without a problem (but someone else did the firing). Again, 2 hours low, 2 hours, medium, and then about 2 hours high before the kiln sitter switched the kiln off. I peeked in the peep hole and the pieces were red hot. This morning, after about a 16 hour cool down, I opened the kiln and nothing. Absolutely nothing. I could have put them in my kitchen oven and gotten the same results. I don't even know where to begin to explore the problem. Any suggestions?