Troubleshooting - Kilns & Furnaces


Kiln Not Firing

Check main electrical supply switch

  • Fuse blown / breaker tripped
  • Cable connection failure

Check kiln controlling contactor

  • Loose connection
  • Contactor failure

Check kiln door / lid switch 

  • Switch switched on
  • Switch incorrectly engages
  • Switch failure

Check Controller

  • Controller not switched on
  • Loose connections
  • Controller faulty
  • Thermocouple circuit inoperative
  • Fuse in controller blown

Kiln Does Not Reach Temperature 

  • Heating element failure
  • Heating element broken in chamber
  • Heating element broken at connection with electrical supply cable to element
  • Ageing elements
  • Too much weight of product and kiln furniture
  • Programmed heating rate set outside the kiln capabilities
  • Top bung left out during the total up cycle
  • Badly fitting (worn) top bung
  • Worn door seals

Uneven Heating 

  • Heating element(s) faulty
  • Top bung left out during the total up cycle
  • Badly fitting (worn top bung)
  • Worn door seals
  • Uneven placing of ware within the kiln chamber
  • Too densely packed ware in the chamber

Kiln Over-firing 

  • Main control contractor fused in
  • Thermocouple pushed back into the insulation
  • Incorrect programming for the type of firing being undertaken

Increased Firing Time 

  • Ageing elements / broken elements
  • Supply voltage low
  • Worn door seals / top bung