Wolf CSO Steam Oven Code E25 / F3: humidity sensor shorted or its duct blocked

What E25 / F3 means

On Wolf CSO convection steam ovens, including the CSO30 series, E25 with F3 reports a short circuit in the climate sensor or in its wiring. The official causes also list a blocked exhaust duct and a blocked duct between the cooking space and the sensor. The oven loses its humidity reading, so steam programs may stop and the code pair appears.

Common causes of E25 / F3

Short circuit in the climate sensor or its wiring
Exhaust duct blocked
Duct between the cooking space and the sensor blocked

✓ One safe check you can try

1. Let the oven cool fully with the door open. 2. Look into the cavity for food debris or foil near the vent openings and wipe them clean. 3. Make sure nothing covers the exhaust path. 4. Restart a steam program. 5. If E25 / F3 returns, stop steaming and call us.

! Why to stop there

A blocked duct deeper in the oven needs panel removal to clear.
A sensor short requires meter testing.
We find which one it is and give a written quote before work.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

→Same appliance

Other Steam Oven codes

U0Wolf CSO Steam Oven Code U0: neutral or overvoltage problem U1Wolf CSO Steam Oven Code U1: L2 supply problem U2Wolf CSO Steam Oven Code U2: mains undervoltage Boiler scaled upWolf Convection Steam Oven Message Boiler scaled up: Descale required E26Wolf Convection Steam Oven Code E26: Climate sensor problem E87Wolf 24-Inch E Series Code E87: Exhaust slide valve jammed or shorted E42Wolf Convection Steam Oven Code E42: Water temperature sensor error E26Wolf 24-inch E Series Code E26: Break or loose contact in climate sensor, or blocked duct

E25 / F3E25 / F3 questions

Can I clean the duct myself?

You can wipe visible debris from the cavity. The ducts behind the cavity wall are for a technician, since opening the oven exposes live wiring.

Why does it matter for steam?

The climate sensor tells the oven how humid the cooking space is. Without a good reading the oven cannot manage steam correctly.

Is the F3 a separate problem?

The listing pairs it with E25 and gives one set of causes, so we treat them as one condition.