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BENTRUP ERROR CODES - EXPLAINED

This page explains what your kiln is trying to tell you in clear, everyday language.

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Thermocouple & Temperature Reading Errors

 

EA1 — Temperature Reading Fault

⚠️ EA1 is not the real fault.

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It always appears with a second code:

  • EA1 + our → thermocouple broken

  • EA1 + udr → polarity reversed or wrong type

  • EA1 + inu → internal electronics fault

 

Fix the second code to resolve EA1.

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“our” — Thermocouple Overrun

⚠️ The kiln cannot read the thermocouple and assumes extreme temperature.

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Causes:

  • Broken thermocouple

  • Loose or dirty connections

  • Wire snapped or unplugged

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Fix: Check the thermocouple is plugged in properly and not damaged.

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“udr” — Thermocouple Underrun

⚠️ The kiln thinks it is below 0°C.

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Causes:

  • Thermocouple wires reversed

  • Wrong thermocouple type

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Fix: Check polarity and type.

 

“inu” — Cold‑Junction Fault

❌ Internal temperature‑reading electronics have failed.

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Fix: Email Cobcraft. This requires repair.

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Thermocouple Polarity

🔧 Correct polarity is essential.

 

  • Red strip on ceramic block = Positive (+)

  • Orange Bentrup cable = Positive (+)

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Reversed polarity causes udr or EA1 + udr.​

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Heating & Firing Performance Errors

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EA3 — Over‑Temperature Shutdown

🔥 The kiln exceeded the programmed temperature by more than 20°C.

 

Let the kiln cool.

 

Email Cobcraft — this may indicate a stuck contactor.

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EA4 — Heating Too Slowly

🐢 EA4 means the kiln cannot keep up with the programmed ramp rate.

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Example: If set to 100°C/hr and the kiln heats at 99°C/hr or less, EA4 appears.

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Causes of EA4

  1. Thermocouple not in the kiln 🎯 If it is outside the chamber, the kiln sees no temperature rise.

  2. ​Cold room or poor insulation 🌬️ Drafts, wind, open sheds, cold studios, kiln too close to walls, gaps in fibre around the base, enlarged vent holes or missing fibre.

  3. Aged elements 🧓 Old elements have higher resistance and produce less power. An 8 kW kiln may behave like a 6 kW kiln.

  4. Broken or melted element wires 🔥 Burnt tails, melted wires, loose terminals, or shorted wiring.

  5. Missing phase (3‑phase kilns) ⚡ A missing phase reduces power dramatically. Customer‑safe check: look for a tripped breaker.

  6. Failed or weak contactor 🧲 A burnt or stuck contactor reduces power.

  7. Simmerstats not on HI (if fitted) 🔄 If off or too low, the kiln is de‑powered.

  8. Lid safety switch not engaging 🛑 If the lid switch does not click, the kiln will not get full power.

 

What You Can Try Before Emailing Cobcraft

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  1. Lower the ramp rate by about 20%. 🧪 This gives the kiln more time to heat.

  2. Use SKIP mode. ⏩ This tells the kiln to heat as fast as it can.

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How to access SKIP:

  1. Go to the ramp rate

  2. Increase to 999

  3. Press UP once more

  4. Display shows “SKIP”

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Useful for kilns with aged elements that still work but cannot meet strict ramp rates.

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Email Cobcraft if:

 

  • You have checked the simple items

  • You have tried lowering the ramp rate or SKIP

  • EA4 still appears

  • You suspect wiring, elements, or contactor issues

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📧 Email keeps all support logged in our CRM system (Tradify).

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EA8 — Ramp Not Achieved

ℹ️ The kiln could not reach the programmed rate, even after extra soak time. Firing continues.

 

EA9 — Uncontrolled Ramp Completed

ℹ️ The kiln skipped a segment because it could not reach the target temperature. Firing continues.

 

Power‑Related Errors

 

E62 — Power Cut (Firing Continued)

🔌 Power returned quickly. Firing continues.

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E63 — Power Cut (Firing Stopped)

🔌 Power was out too long. Restart the firing.

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E64 — Room Too Hot

🌡️ The controller shut the kiln down because the studio temperature is too high. Improve airflow or ventilation.

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Internal Controller Errors

 

EC… — Internal Controller Fault

❌ Electronics issue. Email Cobcraft.

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Ed… — Internal Controller Fault

❌ CPU, memory, or configuration issue. Email Cobcraft.

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Additional Behaviour Notes

 

What Happens After a Power Cut

 

🔄 The kiln decides whether to continue or stop.

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  • If power comes back quickly the kiln continues firing by itself.

  • If the kiln cools more than 50°C The firing stops to protect your work.

  • If the kiln was already warm the controller shortens the ramp time and starts again from the current temperature.

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If the kiln cannot keep up with the ramp

 

🟠 The kiln pauses and waits for temperature to catch up.

  • The kiln pauses

  • The Start/Stop light turns orange

  • It waits until the temperature catches up

  • Then continues

  • If this happens often, the firing will still finish but will take longer than programmed.

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