Unox AF26
Tank missing or safety thermostat fault.
Source: Unox/Unox_XACC-0513-EPLM_ServiceManualAll_CommercialKitchen.pdf
What does Unox AF26 mean?
AF26 indicates the tank is missing or there is a safety thermostat fault associated with it. The oven has detected that a required tank is not present (or not correctly read) or that its safety thermostat has tripped, and it stops to protect the appliance.
Symptoms
- AF26 shown on the control panel
- Oven stops or blocks the affected function
- Alarm clears when the tank is correctly fitted
- Recurring alarm after overheating
Common causes
- Tank not fitted or not correctly seated
- Tank safety thermostat tripped by overheating
- Faulty tank-presence detection
- Wiring fault to the tank thermostat or sensor
Diagnostic steps
- 01
Check the tank is fitted
Confirm the tank is correctly installed and seated, then retry the operation.
- 02
Allow cooling and check the thermostat
If overheating is suspected, let the assembly cool and check the related safety thermostat.
- 03
Test presence and thermostat circuits
With power off, verify the tank-presence detection and the safety thermostat continuity with a multimeter.
- 04
Repair wiring or replace the part
Restore any faulty wiring and replace the thermostat or sensor if it does not test correctly.
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When to call a professional
AF26 combines a presence check with a safety thermostat, so it can indicate a real over-temperature condition. Testing the thermostat and presence circuits requires opening the oven and mains-voltage measurement. If fitting the tank correctly does not clear it, have a qualified Unox technician investigate the safety circuit.
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Open a ticket — free accountOther Unox error codes
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AF02Safety thermostat alarm — the chamber safety thermostat has tripped above its limit.
AF03Temperature probes alarm — a cooking chamber temperature probe is damaged or disconnected.
AF04Communication error with the power board — the control board lost communication with the power board.
AF23Gas alarm — a fault in the gas burner/ignition system (split into multiple AF23 conditions on later software).
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AF39Chamber ceiling temperature too high.
AF41Chamber over-temperature condition (Case 1: T > 150 °C / 302 °F; Case 2: T < 150 °C).
AF43Single-point or multi-point core probe completely damaged.
WF01Chamber temperature probe warning.
WF02Front / chamber temperature probe warning.
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