Wolf CSO Steam Oven Code E67 / F20: Boiler scaled up or sensing issue

What E67 / F20 means

On Wolf CSO convection steam ovens, such as the CSO24 and CSO30 series, E67 (also shown as F20) points at the boiler. The official meaning lists a scaled-up boiler, a kinked silicone hose and a temperature sensing issue. Owners see the code on the display and steam cooking stops, while the oven may still handle some dry-heat modes. The same F20 label is also covered on its own page.

Common causes of E67 / F20

Limescale built up in the boiler
Silicone hose kinked or pinched
Boiler temperature sensing problem

✓ One safe check you can try

1. Let the oven cool fully and empty the water tank. 2. Refill with fresh water and seat the tank firmly. 3. Run the descaling cycle exactly as the use and care guide describes, using the recommended descaler. 4. Rinse, refill and try steam again. 5. If the code returns, stop and call us. Do not open the oven casing.

! Why to stop there

Scale in the boiler can be partly cleared by descaling, but a kinked hose or a sensing problem needs a technician to see it.
The hose and sensor sit behind panels in the oven, which is not an owner job.
Repeated steam attempts on a scaled boiler can make the buildup worse.

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

E26Wolf 24-inch E Series Code E26: Break or loose contact in climate sensor, or blocked duct E87Wolf Convection Steam Oven Code E87: Exhaust slide valve stuck F6Wolf Convection Steam Oven Code F6: Processor and Main Relay Error E51 F0Wolf Convection Steam Oven Code F0: Core temperature probe sensor problem F15Wolf CSO Steam Oven Code F15: niche running too hot F1Wolf Convection Steam Oven Code F1: Food probe error F17Wolf CSO Steam Oven Code F17: climate sensor overtemperature F10Wolf Convection Steam Oven Code F10: Control moisture or water tank valve

E67 / F20E67 / F20 questions

What is E67 on my Wolf steam oven?

It is a boiler code on CSO convection steam ovens. The listed reasons are heavy scale, a kinked silicone hose or a temperature sensing issue, so a technician checks all three.

Is F20 the same thing?

Yes, F20 is the label some displays use for the E67 condition. Both point to the boiler, so the same checks apply and the repair path is the same.

Will descaling clear it?

Sometimes, if scale is the only cause. If the code returns after a proper descale, the hose or the sensing circuit needs a look, and we quote that in writing first.