Why is my Kiln or Oven Not Heating Properly?

We all love our kilns and heat treat ovens. I'm even thinking about creating a big sign for Gail's studio that says "Have you hugged your kiln today?"💖 But, let's be honest... using a kiln comes with its share of emotional ups and downs. Knowing how to be a good troubleshooter can help at the time when you are starting to feel the most frustrated. So, let's look at some kiln troubleshooting tips from our friends @ Evenheat!

⚠️#1 issue - Why is my Oven Not Heating Properly?
  • Start by check for a "blown" fuse or tripped circuit breaker. This is a good time to double check that these devices are properly sized... meaning do you have the correct breaker for the number of amps your kiln requires. 
  • Check for voltage at the kiln plug/receptacle. 
  • Kiln not plugged in. (Don't laugh, it's happened!)
  • For digital controllers, check the control fuse located on the control panel. 
  • For kiln sitter controllers, make sure the plunger is pushed in or the kilns' power switch is ON. Also, check the limit timer as it may be set to "0".
  • Make sure kiln is plugged into the correctly specified receptacle. 
  • Possible element failure. It's always wise to have extra elements, pins, and relays available!
  • Kiln panel component failure.
  • Check for worn or broken wires. This is especially important as damaged wires can be an immediate fire hazard. 
⚠️#2 - Fires Too Slowly
  • Elements are wearing out. Elements age when fired and increase in resistance. Firings gradually take longer, and longer until the kiln will not reach temperature. Replace all elements. High firings wear the elements out faster than lower firings.
  • Make sure all elements are firing. You can check this by carefully lifting the lid while the kiln is on to make sure all elements are glowing. In some kilns, especially kilns with Digital Controllers, the top and bottom coils appear to become hot quickly while the center elements appear to be slow in becoming hot and are less bright. WARNING! Do not touch the elements when doing this as they are HOT!
  • Voltage too low. As voltage falls, so does power. Check voltage while under load for a more valid reading. Sometimes, the voltage may vary in certain areas due to heavy electrical use. This is especially true in the summer with a heavy demand for air conditioning and refrigeration. Older homes may also have a lower voltage due to older wiring. 
  • Improper operating voltage. Check the rated voltage (printed on the nameplate) against the measured voltage. A kiln designed for 240V will be slower when connected to 208V.
  • Long runs of wire from the main service can cause lower voltage, which lowers power.
  • Service wired incorrectly. The kiln may have inadvertently been connected to 120V instead of 208 or 240V. (Yep... this has happened, too!)
  • Loose connections between the fuse box and kiln.
⚠️#3 - Fires Too Quickly
  • Improper operating voltage. Check the rated voltage (printed on the nameplate) against the measured voltage. A kiln designed for 208V will fire faster when connected to 240V. This situation is dangerous and may cause amperages to exceed design limits. Do not allow this condition to exist and cease using the kiln immediately.
  • Check element ohms to make sure they meet the factory specifications.
  • Improperly programmed digital controller. ALWAYS double check your programs! Sometimes, it's the easiest answer!
    Please remember that for many of these suggestions, it is highly suggested that a licensed electrician is called to assist you with troubleshooting these remedies!

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