I am having trouble with my kiln-sitter. What do I do?

strict warning: Only variables should be passed by reference in /home/hotkilns/public_html/sites/all/modules/captcha/captcha.inc on line 61.

Search Knowledgebase

Knowledgebase FAQ

  • See the Sales FAQs for Frequently Asked Sales and Preorder Questions
  • The Knowledgebase is organized into a series of questions and answers having to do mostly with technical troubleshooting and understanding of kilns.
  • Although we write this for our own kilns many of these articles apply to other makes - although L&L takes no responsibility for that.
  • Many Knowledgebase articles have Actions, PDFs and Videos associated with them.
  • Actions are specific actions for you to take during the troubleshooting or repair process.
  • Each Action may also have Videos and PDFs associated with it and, in addition, specific Cautions.
I am having trouble with my kiln-sitter. What do I do?

Kiln Sitters in general

  1. First, download the appropriate kiln-sitter manual from L&L’s website- (PDF Library/ Controls and Thermocouples section.)
  2. Never let the kiln-sitter shut off the kiln unattended- always come back to check on it.
  3. The kiln-sitter tube assembly needs to be routinely replaced depending on usage- especially if the sensing rod (the rod that sits on top of the cone) is getting thin or bent, or if the cone is looking puffy once the kiln cools down.  If not replaced and left unattended the kiln could dramatically overfire.
  4. On unvented kilns, the kiln-sitter tube assembly must be replaced much more frequently.


If the kiln-sitter does not bend the cone enough or does not shut off soon enough:

  1. VERY IMPORTANT- see the first couple pages in the kiln-sitter manual for step-by step adjustments. 
  2. Or see the article here about how to adjust.

White Button does not stay in

  1. Be sure the timer is on. 
  2. Be sure the weighted trigger (swings up and down on the front of the kiln-sitter) stays in the upright position when you push the button. 

If white button still does not stay in, then EITHER:

1.  There is a little spring missing on the flat metal plate on the back-side of the kiln-sitter faceplate that pivots into a slot cut into the button to hold the button in.  See the exploded diagram of the kiln-sitter in the kiln-sitter manual to see where the spring is supposed to go.


2.  Cords or wires inside the kiln-sitter box have moved around enough to press against this same metal plate, not allowing the spring to pivot it into the white button’s slot.


3.  The kiln-sitter is corroded enough that this same metal plate cannot pivot, even with the spring’s tension.


4.  One of the connection points on the ceramic connection block (that the button is attached to) is overheated enough to partially melt the button so the metal plate cannot pivot into the slot.

White Button stays in, but there is no power

  1. Reset kiln breaker.  

Still no power?

  1. Set switches on the control box all to HIGH. 
  2. With the weighted trigger in the down position on the kiln-sitter face plate, jiggle the button on the kiln-sitter in and out and look for the indicator lights near the switches to flash on and off.  Sometimes the contact points cannot line up properly on the ceramic connection block. Jiggling the button can re-align the contact points.  

Still no power?

  1. Listen for the timer ticking when the button is pressed in.  
  2. If you don't hear it, you should check for an overheated or disconnected place in the kiln-sitter or back towards the breaker, or to see if the breaker is bad. 
  3. If you hear the timer, look for the overheated/ disconnected spot after the kiln-sitter in the main control box.  UNPLUG the kiln and look for these overheated places. 

Multi-meter testing by an electrician with help from Tech Support over the phone is next step if nothing is found.

Additional Actions to Take

  • Power relays are one of the most important components in your kiln. They execute the will of the computer controller, giving power to the elements only when requested. These power relays are also mechanical switches which will wear out over time. Worn out relays can be the cause of slow or incomplete firings, error codes (E-1, E-d), etc. Other more obvious signs of relay failure are if a zone is lagging behind in temperature considerably or if you notice an entire ring of elements not heating/glowing. 
  • The surest way to test your relays is by using a multimeter to check input, output, and signal voltage. If you do not have access to a multimeter you can run a paper test, which will give you some indication of whether or not you have a relay out.


  1. One way to check the relays (or bad elements) is to check the temperatures of each zone by pressing "1", "2" and "3" in sequence and recording the temperatures of each thermocouple at intervals over the length of the firing. If one zone is consistently firing at a lower temperature then you probably have either burned out elements or a bad relay.
  2. If the relay does not make a soft clicking noise when the kiln is turned on try turning the kiln off and on and then restarting the program.
  3. Remove panel.
  4. Set your multi-meter the approximately 24 volts AC. Check the voltage coming into the coil of the Power Relay. You can tell which wires these are because they will be the small wires coming from the control. This test will tell you if you are getting power to the relay coil which actuates the relay. Unless the relay is actuated by the control you will get no output from the power side of the relay.
  5. With panel plugged in and firing check output from Power Relay with your digital multi-meter. The meter should be set to the next highest voltage above 240 volts AC. Output should be approximately the rated voltage of the kiln when it is supposed to be calling for power to the elements.

CAUTION: LIVE ELECTRICITY IS INVOLVED WITH SOME OF THESE TESTS. This test should only be done by an experienced person familiar with electricity.

  1. Make sure power cord is plugged in.
  2. Reseat the plug. Pull it out of the receptacle and put it back it. This will reseat the connections.
  3. Also, sometimes the female socket and/or the male spades get oxidized (which can resist the flow of electricity). Reseating them can disturb this oxide layer.
  4. When you do this examine the plugs for any signs of burning or overheating. If the spades look oxidized you can rub them with steel wool to shine them.
  5. Make sure the plug is held firmly and that the springs inside the receptacle seem to be working.
  6. Look for any damage on the cord itself.
  7. Make sure the cord is not touching the kiln case.

CAUTION: This test should only be done by an experienced person familiar with electricity and its dangers.

  1. Make sure the circuit breaker or fused disconnect switch is turned on.
  2. If you have a circuit breaker flip it back and forth to make sure that it is really on. Some circuit breakers, if they have tripped, will not be obviously in a tripped position. By flipping it back and forth you will reset the circuit breaker.
  3. Check voltage of your power supply at the receptacle using your multi-meter set to the next highest AC voltage above 240 (typically this will be 600 volts but may be 250)
  4. Check fuses for voltage continuity. You can do this with your multi-meter.
  5. Make sure fuses or circuit breaker are/is the proper amperage and type. See your wiring diagram for the required fuse type.

CAUTION: This test should only be done by an experienced person familiar with electricity.