We have an old evenheat kiln that we're struggling to master. It's a 4320 model but with the 4 toggle switches and not the 4 dials. Our problem is that the top element takes way longer to heat up than the other 3. We did a paper test and initially it appeared that the top element wasn't warming up at all, after 30 seconds the lower 3 elements had all scorched their pieces of paper while the top was still unmarked.
We took the cover panel off and tightened a couple of wires that appeared overly loose, one going to the top element and one going to the grounding point. The top element now at least get hot enough to scorch the paper but takes at least twice as long as the other elements.
So the switch works and the element works but we're stuck as to where to go next. The only thing I can see different with the top element circuit and the others is that the top circuit includes a "therm-o-disk" which appears to be some kind of bimetallic thermostat. Could that be the cause of our issue? Or could it simply be that in this model of kiln the top element doesn't get so hot because it's at the top where all the heat rises to anyway.
Any tips would be greatly appreciated. We're really struggling to get consistent glaze firings in this kiln and now there's two of us potting away going back to the small kiln would be painful, not to mention lead to further global warming.