Kiln Sitter Troubleshooting
Here are some of the most common problems you may have with the "Kiln sitter" and the proper solutions.
Over or Underfiring
The problem of a consistent over or underfire is from improper adjustment of the "Kiln sitter" trigger and claw assembly. Re-adjust the "Kiln Sitter" according to the operators manual on pages 3-4.
The problem of erratic firings (some may be correct and others overfired) can usually be traced to a corroded swivel on the tube assembly. To check for this, remove the guide plate and look at the area of the tube assembly where the rod comes through the tube. If any corrosion can be seen on the outside area around the swivel, replace the tube assembly. Pages 12-14. After replacing the tube assembly, re-adjust according to the operators manual, pages 3-4.
If you find that this is a problem or suspect that it might be a potential problem, be sure to vent the kiln adequately for it's size and load. A minimum for the smaller kilns would be one peep hole and on the larger kilns, at least two (top and bottom).
If you find that you need to increase the venting or feel you need to close the kiln, leave all the peepholes open until you reach at least 1,100°F (reddish-yellow heat stage) before you shut the venting down.
Plunger Button Will Not Engage
If you find that the plunger button will not engage, check to see if the timer knob is on the "OFF" position. It must have some time shown to operate correctly. If you find the cam or lock assembly will not move to engage the slot in the plunger button, assume it is stuck to the face plate by something foreign (either corrosion or some sticky substance). If this is the case, on an "LT" model rotate the knob past the twenty hour mark while at the same time, pushing in on the plunger button. This should force the cam into the slot of the button, manually release the weight to be sure the cam disengages the button properly. If this doesn't work, the procedure for all models is the same, remove the face plate and clean or replace the cam or lock assembly. Be sure there is no corrosion or interruption of the surface.
If you have any question as to the quality of the part, place it!
NEVER USE ANY TYPE OF LUBRICANTS ON THE "KILN SITTER"
Plunger Button Melting Or Deforming
The plunger button will deform if there is too much heat produced at the back side of the switch. Normally the unit will shut off at this point. This is to prevent the connections on the back side of the switch from burning off. If you find this has happened, you must check the connection on the back side of the switch for damage to the wires or connectors. If you find any damage that is heat related, be sure to cut back the wires until there is no more corrosion and replace the connectors with the proper size. Ring connectors come in both wire and stud size. On the larger ampere kilns, you may want to sweat solder the lugs on to the wire. This helps reduce any connections problems. If you find any problems with the switch assembly, please refer to number five.
Switch Or Contact Problems
If you encounter any burning or sticking of the contacts, you must replace the contacts and determine the cause of the problem. You may refer to the number four trouble shooting answer to find possible reasons for your switch failure. If after inspection, you determine that the damage is heat related, go through the steps outline in number four.
The switch should be inspected for any heating of the center post spring or blackening of the porcelain block. If you find either on of the above, replace the switch assembly with a new complete assembly.
*NOTE: The screws on the switch should always be checked for tightness. Heating and cooling can loosen the connections.
Cones Sticking or Breaking
If you find that the cones are breaking, stretching or sticking, the cone supports should be replaced. If they are rough, kiln wash should be used lightly. The cone needs to slide on the cone supports for a reliable firing. A small nail polish bottle cleaned and filled with a watery solution of kiln wash works well to coat the supports. Rub kiln wash off the cone supports with your fingers after each firing and re-apply.
Chipped Or Broken Tube Assembly
If you find that the tube assembly is chipped where the cone supports are held at the end of the tube assembly, replace the tube. If the tube assembly moves or can be rotated, replace the tube assembly.
Sensing Rod Bent or Tapered
The sensing rod will begin to taper and wear with use depending on the type of firings. If you can see any tapering of the rod assembly, replace it. If your tube assembly is older, be sure to check the swivel area for corrosion as outline in number two. If there is any doubt, replace the tube assembly.
If you suspect that the timer is not operating properly, set the timer for one half hour to check the operation for a short test. There is no need to have the element switches on for this test. If you find that this test functions the motor properly, you may test it along with your next firing. Keeping a record of where it started and how many hours were left after the firing. If after these tests you find the motor is not functioning properly, replace the timer motor.
Remember that on all the "Kiln Sitter" models, the rod assembly should move without any obstructions. All adjustments are done with the gauge in place. Remember to remove it before firing!