21 year old Skutt Clamshell kiln issues

[Val Eibner]

just replaced relays and had 2 good firings, but a recent firing was going
great until it reached 1250 degrees with 2 min. H then instead of going
to 410 to 14 25 temp. it started to go in reverse. Cooling slowly, which I have
not seen it perform this way ??? in 20 years. Seems all elements are going
on and no burnt out wires?? I reset controller, but I am puzzled.
Any ideas? Thanks, Val

[Brad Walker]

That's an odd situation. Normally, if elements were bad it would generate an error message (Failure to Heat) before it started cooling.

Has the problem repeated itself? Have you double checked the firing schedule to make sure you programmed what you thought you did?

[Val Eibner]

I selected different program # and reset the controller. Have put in new
relays. The kiln fired to temperature. Fingers cross that it will last a wee
bit longer.