Friday, May 20, 2011

Kiln Troubleshooting

A couple of weeks ago - I started to have trouble with my kiln. My studio is a room over from my office - and the kiln is out of sight from my desk - but you all know that distinctive click that the relays in your kiln makes? That sound carries a fair ways. So - I'm sitting here at my keyboard, it's early in the day, and suddenly - I hear beeping - followed by the kiln "clicking." (I have the Paragon F120, btw.)

Well - that's odd, thinks I, and I get up and go look. The kiln is happily sitting there, displaying "Idle" and the room temp. Ok - go back to work.

It took me a while, but finally, I caught it in the act - the display would come on full - lighting all the LEDs and giving me 88.88 on the readout, then it would beep, and then the relay would click, the kiln would heat up a degree, and then it would shut off and go back to idle.

Well - a kiln that decides to spontaneously heat up a degree doesn't sound like a good thing, - it might be habit forming and decide next go for 2 degrees, or a 100, or a 1000! So I shut it off and called a friend. She suggested that sometimes the fuse can be getting "weak" - and I should replace the fuse. Fuses are cheap, (replacements at Canadian Tire), so I did that. And thank you to whoever decided that the fuse should be easily accessible on the front of the kiln. Seriously - thank you. Hint. Put the serial number on the front too.

That appeared to stop the spontaneous turning on and off, but, to be safe, I left it off when not in use, so it's hard to say. It was a few days later that I managed to clear some time to actually torch - so I fired up the kiln - and it had been on an hour - when it spontaneously failed, all 8s readout - alarm beeping, and then when back to running.

Only now - when I checked - it was running program 01. Program 04 is my normal annealing program. (I think my rationale to use my most commonly used program buried down the list was that if someone comes along and randomly pushes buttons and messes up a schedule - they are less likely to mess up Program 04 than 01.)

Program 01, I have set up as a fusing schedule. So the temperature rapidly overshot my normal garaging temp, and started to shoot up into the 4 digit area. I reset the program, but the kiln continued to fail and reset itself to running Program 01 from the beginning. Ok - call it a night.

Next day - I talked to Paragon kilns - described the saga in detail - to which they listened patiently, and then had me repeat the conditions for the failure - to determine whether the lights on the side came on - which I hadn't noticed. (I realize now - the Program/Review/Run lights on the side were not well lined up with the holes they shone through - which made them difficult to see unless you duck your head down - so I have been pretty much ignoring them.) Once I knew that (all of them came on at once) - I called them back - and the verdict was - the digital controller board was toast.

Paragon overnighted a new controller to me - it was in my hands by 10 the next morning. It was the work of a few minutes to replace the controller. Hubby did it - it's electronics, so he finds it interesting. This is what he did. Unplugged the kiln. Took out the four screws holding the controller in place - the display and board came out together. Unplugged the wires from the left and the right. Plugged them into the new controller. On the sensor (thermocouple) side, he matched the wire colours to the blocks on the board - although he says this is not strictly necessary. Put in back into place, reused the screws to put in place. Plug the kiln back in. Well - actually - he also unscrewed the board from the display panel before discovering that the new board had it's own display panel, but you don't need to duplicate that step. ;-) I only mention that because you can see it in this photo.

Kiln reassembled and starting a test run.

Overall - it took longer to find a Phillips screwdriver than it did to remove and replace the board.

Paragon kilns - both the kilns and the company - continue to impress me. This kiln has been working flawlessly for about 5 years, and when I called with a problem, they were super helpful on the phone, and had a replacement part to me the next day.

I wish the whole world was like that: helpful, competent and efficient. What a nicer place it would be. ;-)


  1. Glad you have a kiln again! It's good to hear about the service you got from Paragon. No one wants to think they'll be left high and dry.

  2. Good to hear as I have a Paragon Kiln too... glad you're back up and running x