A few years back, I purchased my first brand spanking new electric kiln. I have had a nearly permanent grin on my face since then.
While my kiln is beautiful and shiny now, I know the day will eventually come when I will have to replace the kiln elements. I've always fired in other people's kilns so I have never had to do any of this sort of kiln repair or maintenance before. Today I thought I would post an excerpt from our new handbook Electric Studio: Making & Firing for all of you out there who might be in the same boat as me. I am definitely going to keep this one handy for that inevitable day when my kiln elements go kaput. - Jennifer Harnetty, editor.
Kiln Repair: Instructions for Replacing Elements on an Electric Ceramic Kiln
To check the elements in your electric pottery kiln, a visual inspection can reveal some information (figure 1). To check to see if current is getting through, you can turn on the elements when the kiln is empty and peek into it and see if any elements are dark. A kiln repair person uses a volt/amp/ohm meter to test each element, and you can purchase one of these online or at your local home center for between $20–$30.
Today, computer kiln controllers, depending on the model, can provide anywhere from an error message to a full-blown diagnostics of your electrical system. Make sure you read the owner's manual for complete information or visit the manufacturer website and check out their support materials. As a visual/art person, I hate to read this type of stuff. Fortunately, Skutt and other manufacturers have videos of how to replace elements, thermocouples, bricks and etc, on their sites and on YouTube. Seeing someone else do it and being able to pause and watch it again can give you great information and the confidence you need to repair your electric kiln.
More and more, the electric kiln is being used not just as a means to fire work, but as a creative tool. Our newest handbook Electric Studio: Making & Firing, is designed to help you help you maximize the potential of your electric kiln and use it as an integral part of your creative process. You’ll discover how to select the kiln that’s right for you, learn how to maintain it and make simple repairs, and and best of all explore various firing techniques to achieve spectacular results once reserved only for large fuel-burning kilns! This book takes you way beyond your owners manual!
You need the kiln model, voltage, and phase to order elements. These specifications are critical to the safe and efficient performance of your electric kiln. Elements can vary between models and within the same kiln. So be sure to order the factory-recommended elements for your model and install them in the correct positions. Even if just one element is bad, it is recommended that you replace all elements at the same time since another element could fail on the next firing. I have a KM1027 Skutt Kiln that's engineered to fire evenly partly by having top and bottom elements that are hotter than the center elements. They come packaged with this information on them. If your elements are different configurations, replace only one element at a time so you don’t mix them up.
Replacing Kiln Elements - Step-by-Step Instructions
Remember that kiln repair instructions vary from kiln to kiln, but these basic instructions are valid for the vast majority of them. Make sure you get the proper instructions for your particular ceramic kiln.
1. Unplug the kiln and/or turn off the breaker.
2 Remove the screws on the control box cover.
3. Remove the wires from the controller panel from the kiln figure 2).
4. Disconnect thermocouple wires and label each wire as you go along with a marker and masking tape (figure 3).
5. Unload the tension on springs and remove the lid. Place it gently on a flat surface.
6. Unlatch the sections and place one kiln section at a time where you can comfortably access it (figure 4).
7. Cut the feeder wire off that leads to the elements as close to the barrel connector as possible, then cut the barrel connector off the element pigtail. This will release the element to be removed.
8. If your kiln requires wire pins to hold in the elements, use needle nose pliers, carefully remove the element pins in the angled brick joints (figure 5) and then slowly and gently remove the element.
9. Thoroughly vacuum debris from the element groves.
10. Check you have the correct replacement element and cut off the end loop on the pigtail so you can push it through the terminal hole.
11. Elements are engineered with slight bends that will match the angled brick corners that allow them to rest nicely in the grove of the brick. Slight adjustments can be made by stretching or compressing the element (figure 6).)
12. Soft brick grooves require element pins. Once the elements are in place, insert new pins in the corners of the bricks in a downward angle. New pins come in the replacement element bag (figure 7).
13. Replace the porcelain insulators on the outside of the kiln sliding them over the ends of the element pigtails
14. Pull the element pigtail gently through the hole as far as it will go and mark it 5/16 beyond the porcelain insulator (figure 8). Using side cutters to cut it to length (figure 9).
15. Strip ¾ of the insulation off the correct feeder wire and bend the exposed wire over so it is doubled. This allows for a better fit in the barrel crimp connector.
16. Attach the connector by first gripping one connector supplied with a dimple-crimping tool. Make sure the crimp point is lined up over the place where you wish to make the crimp. Reach inside the kiln chamber and push the element through the hole as far as it will go and slide the connector over the pigtail so the end of the pigtail is in the center of the connector and crimp down hard. When you let go the connector and porcelain insulator should be snug against the heat shield. Place the feeder wire/wires into the other end of the barrel connector and make a secure crimp. Different manufacturers have different hardware to connect elements to the feeder wires such as barrel fasteners that hold the elements and feeder wires together by tightening a screw down onto a small metal plate inside a small open metal rectangle (figure 10). Use what is recommended.
Tips for Success
Do only one section of the kiln at a time to keep from getting confused. If your work is interrupted, it will be easy to pick up where you left off. Run diagnostics if your controller has the capability. If it checks out, run a test bisque fire to make sure all was fine. Use self-supporting cones to check on all firings. Cones indicated this firing was right on. I’ve had hundreds of successful firings in this kiln and with the new elements I look forward to hundreds more.
Originally published September, 2012.
For more great electric kiln firing techniques, be sure to download your free copy of Techniques and Tips for Electric Kilns: Inspiration, Instruction and Glaze Recipes for Electric Kiln Firing.