These Kiln Sitter pointers will help prevent melt downs. These are very basic, but sometimes it is easy to forget the basics:
1) Warn others not to touch your kiln while it is firing. Bumping the Kiln Sitter release claw can move the guide plate out of alignment, preventing the actuating rod from dropping. This will over-fire the kiln. (The actuating rod rests on top of the small cone in the Kiln Sitter. The release claw is on the other end of that rod. The guide plate adjusts the release claw from side to side and is held in place with two screws.)
2) Place only stable ware inside the kiln near the Kiln Sitter tube. If someone bumps the kiln, an unstable stilted piece could fall against the actuating rod, causing an over-fire.
3) Keep ceramic shelves at least one inch above or below the Kiln Sitter tube. If jarred, a shelf that is even with the tube could press against the actuating rod, causing an over-fire.
4) A piece of exploding greenware could lodge against the actuating rod, causing an overfire. Make sure greenware is bone dry before firing.
5) Keep a record of your firings so that you will know how long a firing should take. Then set the Limit Timer on the Kiln Sitter for 30 minutes to an hour longer than the expected firing. (If your Kiln Sitter does not have a knob, it doesn't have the Limit Timer.)
6) Learn to estimate the temperature inside the kiln by the color of light around the lid. This will help you to know at a glance if the kiln is over-firing.
7) Place witness cones on the shelf and position them so you can see them through a peephole. If you ever suspect that the kiln is firing too long, check the cones.
8) Never leave the Kiln Sitter unattended during firing. Though it shuts off the kiln automatically, it still needs the operator's attention.