Wolf CSO Steam Oven Code E81 / F23: Evaporator draining error

What E81 / F23 means

E81, shown on some displays as F23, is an evaporator draining error on Wolf CSO convection steam ovens such as the CSO24 and CSO30 series. In plain words, the oven could not empty the evaporator the way it expects after steaming. Owners see the code, and steam operation is blocked until it is dealt with. The official entry is short, so a technician checks the drain path and the drain pump.

Common causes of E81 / F23

Evaporator not draining as expected
Drain path restricted
Drain pump not removing water

✓ One safe check you can try

1. Let the oven cool and wipe up any water in the cavity. 2. Empty the tank and refill with fresh tap water. 3. Switch the oven off for one minute and back on. 4. Try a short steam cycle. 5. Still seeing E81 or F23? Give us a call. Do not open the casing.

! Why to stop there

The evaporator and drain path are inside the oven.
A restriction or pump problem cannot be told apart from outside.
Repeated cycles add water to a system that is not draining.

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

E81 / F23E81 / F23 questions

What is the evaporator in a steam oven?

It is the part that turns water into steam. After cooking it has to drain, and E81 means it did not drain correctly. On site we look at evaporator not draining as expected and drain path restricted, then quote the repair in writing.

Is F23 the same code?

F23 is the label for the same family of drain problems and also covers E73. Either way, the drain path and pump are what we test. Starting point for us is usually evaporator not draining as expected, with the price written down before any work.

Is it safe to wait for the visit?

Yes, just leave the oven unused for steam. Wipe up standing water and call us. We write the price down before any repair. We would also rule out drain path restricted before recommending anything.