Wolf CSO Steam Oven Code F23: Evaporator or drain pump draining

What F23 means

F23 on Wolf CSO convection steam ovens, such as the CSO24 and CSO30 series, is a drain-related display label. It stands for the E81 evaporator draining error and for E73, where the drain pump pumps off too little water. Owners see F23 and the oven will not continue with steam. The checks center on the drain path and the pump rather than on the controls.

Common causes of F23

Evaporator draining error
Drain pump removing too little water

✓ One safe check you can try

1. Let the oven cool and wipe up any standing water. 2. Empty the tank and refill it with fresh tap water. 3. Switch off at the breaker for one minute. 4. Run a short steam cycle. 5. If F23 returns, call us. Do not open the casing or reach into the drain.

! Why to stop there

The pump and evaporator are inside the oven.
A drain restriction cannot be seen from outside.
Repeated steam cycles add water that cannot leave.

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.

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Other Steam Oven codes

F2Wolf CSO Steam Oven Code F2: water temperature sensor short F13Wolf Convection Steam Oven Code F13: Cabinet opening too hot F3Wolf CSO Steam Oven Code F3: climate sensor short or break F4Wolf CSO Steam Oven Code F4: exhaust slide motor problem F5Wolf CSO Steam Oven Code F5: control board error group F7Wolf CSO Steam Oven Code F7: boiler heating problem F9Wolf CSO Steam Oven Code F9: cooking space not sealed U0Wolf CSO Steam Oven Code U0: neutral or overvoltage problem

F23F23 questions

What are E81 and E73?

E81 is an evaporator draining error. E73 means the drain pump removes too little water. F23 is the label that can stand for either. On site we look at evaporator draining error and drain pump removing too little water, then quote the repair in writing.

Could the water I use matter?

For E73, yes: very low conductivity or foam can play a part. Regular tap water is the safest choice. Starting point for us is usually evaporator draining error, with the price written down before any work.

What will you do on a visit?

We test the drain path and pump, give you a written price, and repair what is confirmed. We would also rule out drain pump removing too little water before recommending anything.