Error Code
high
Unox OVEN – Control Panel or USB Board Defective – Buzzer Does Not Sound
On your CHEFTOP and BAKERTOP MIND.Maps™ unit, a non-sounding buzzer often indicates…
Unox OVEN - Metal Dust on Contactors / Defective Power Board Relay - Contactors Chattering
Critical / Stop Operation
Warning: The information provided here is for educational purposes only.
Working with commercial kitchen equipment involves high voltage, gas, and high temperatures.
We strongly recommend contacting a certified service technician for any repairs.
We are not responsible for any damage or injuries resulting from DIY repair attempts.
This information is provided 'as is' without any guarantees of completeness or accuracy.
TLDR
On your CHEFTOP and BAKERTOP MIND.Maps™ unit, contactor chattering or a suspected defective power board relay indicates an electrical fault that can impact oven performance and safety. Begin by measuring the power supply to the contactor coil between pins A1 and A2. If this supply is unstable or incorrect, the power board needs replacement; otherwise, clean or replace the contactors themselves.
Technical Details
Repair Steps:
- Safety First: Before beginning any work, ensure the UNOX CHEFTOP or BAKERTOP MIND.Maps™ oven is completely disconnected from its main power supply.
- Measure Contactor Power Supply: Access the oven’s electrical compartment where the power board and contactors are located. With a multimeter set to V AC, carefully measure the power supply voltage between pins A1 and A2 of the contactor in question. You should observe a stable value of approximately 230 V AC.
- Evaluate Power Board: If the measured voltage is unstable, absent, or significantly deviates from 230 V AC, this indicates an issue with the power supply to the contactor coil. In this scenario, the power board is likely defective and requires replacement.
- Test Contactor Operation (If Power Supply is Stable): If the 230 V AC power supply to the contactor is stable, reconnect power to the oven (safely). Initiate any cooking program. While the oven is running, carefully open and close the oven door a few times. Observe if the contactor chattering issue persists during this operation.
- Clean Contactor Contacts: If the chattering persists after the operational test, power down and disconnect the oven again. Use dry, compressed air to thoroughly clean the contacts of the contactors, ensuring all metal dust or debris is removed. Exercise caution not to damage any delicate components.
- Replace Contactors: If cleaning the contacts does not resolve the chattering issue, it indicates that the internal contacts or coil of the contactors are worn or defective. In this final step, the faulty contactors must be replaced with new, genuine UNOX parts.
Common Questions:
Q: What causes contactor chattering in my UNOX oven?
A: Contactor chattering in UNOX CHEFTOP and BAKERTOP MIND.Maps™ ovens is typically caused by metal dust accumulating on the contactor’s electrical contacts, a defective relay on the power board providing an unstable voltage, or worn internal components of the contactor itself.
Q: How do I correctly measure the contactor power supply?
A: To measure the contactor power supply, first, ensure the oven’s power is off. Then, set your multimeter to AC voltage (V AC) and place the probes between pins A1 and A2 of the contactor. A stable reading around 230 V AC is expected.
Q: Is cleaning contactors with compressed air a safe practice?
A: Yes, cleaning contactors with compressed air can be effective, provided the oven is completely disconnected from power and appropriate personal protective equipment (PPE) is worn. Ensure the air is dry and apply it in short bursts to dislodge debris without forcing it further into components.
When to call a technician
For this error, we recommend calling a certified technician. Do not continue operation or attempt repair yourself.
- Equipment shows a critical or stop-operation fault.
- You smell gas, burning, or see smoke or sparks.
- Error returns after following the steps above.
- You are not trained to work on this equipment.
- Warranty or safety could be affected by DIY repair.