Convotherm Combi Oven Error Code E25.1: Condenser Sensor Ground Fault
E25.1 on the older Convotherm OES, OEB, OGS and OGB ovens means the condenser sensor (B3) has a ground fault. The manual's only response is to contact customer service. Steam functions may stay off until the circuit is repaired.
Medium: steam functions may stop, while dry cooking can continue.
- Code
- E25.1
- Maker
- Convotherm
- Equipment
- Combi ovens
- Applies to
- Convotherm OES / OEB / OGS / OGB (older, pre-C4)
What does Convotherm error code E25.1 mean?
Sensor B3 sits on the condenser, where hot exhaust steam is cooled, and its signal should travel only along its own two wires. A ground fault means that signal has found a second path to ground, usually because the insulation on the cable has worn through or because water has crept into a plug. The control then sees a value that cannot be real and shows E25.1 instead of trusting it. Wet, hot conditions near the condenser wear cable insulation over time, and the problem can come and go as the cable heats, cools and dries, so the oven may behave for a while and then fail again. The manual's response is to contact customer service. Finding the damaged spot means measuring the cable with the oven open, and that is not an operator task.
Affected models and control systems
Older Convotherm combi ovens in the OES, OEB, OGS and OGB line, which came before the C4. The source is that line's English user manual, a translation of the original, with no revision number printed.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- E25.1 on the display
- Steam functions stop or are refused
- Code returns when the oven is hot and damp
- Dry-heat programs may still run
Possible causes
Likely causes — what usually sits behind error code E25.1 on this control. A technician confirms which one it is before any part is replaced.
- Cable insulation worn through near the condenser
- Water inside the sensor plug after a wash-down
- Sensor body in contact with a metal bracket
- Condenser sensor shorted inside its housing
Safe checks before calling for service
- Switch the oven off and let it cool completely.
- Keep water and cleaning spray away from the back of the oven while it waits for service.
- Restart once after the oven has dried and see whether the code returns.
- If E25.1 appears again, stop using steam functions and contact customer service.
- Tell the technician whether the code came and went with the oven's temperature.
How a technician diagnoses error code E25.1
- Read E25.1 and the history, and note whether the code appears cold or only when hot.
- Disconnect sensor B3 and test the sensor and cable separately for a path to ground.
- Inspect the cable and plug for worn insulation, heat marks and moisture.
- Dry out the connector and retest to separate a damp plug from a damaged cable.
- Replace the cable section or sensor that fails the test.
- Run a steam cycle and watch the condenser reading.
- Tracing a ground path means measuring cables that run beside line-voltage parts.
- Intermittent insulation damage needs the oven heated and cooled during testing, which takes time and care around hot surfaces.
- Condensation near the exhaust path can scald if panels are opened at the wrong moment.
How error code E25.1 differs from similar codes
E25.0 is the same sensor with an open circuit instead of a ground fault.
Technical reference
- Maker documentation
- Convotherm owner support
- Edition
- No revision/part number found in the text read
- Models / control
- Convotherm OES / OEB / OGS / OGB (older, pre-C4)
- Section
- Troubleshooting, Errors and required responses, pp. 161-162
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Convotherm combi oven error codes
What is a ground fault on a sensor circuit?
The sensor signal is reaching ground by a path it should not have, so the control sees a wrong value.
Why does E25.1 come and go?
Heat and moisture change how well a damaged cable insulates. The path can close when the cable is hot and open again when it dries.
Can I use steam in the meantime?
It is better not to. The control cannot trust the condenser reading, which is why it stops steam.
Need help with Convotherm error code E25.1?
A technician confirms the cause on site and gives you the price in writing before any work starts.