Convotherm Combi Oven Error Code E25.0: Condenser Sensor Open
E25.0 on the older Convotherm OES, OEB, OGS and OGB ovens means the condenser sensor (B3) has an open circuit. The manual's only response is to contact customer service. Leave the oven off the steam functions until a technician has tested the sensor circuit.
Medium: steam functions may stop, while dry cooking can continue.
- Code
- E25.0
- Maker
- Convotherm
- Equipment
- Combi ovens
- Applies to
- Convotherm OES / OEB / OGS / OGB (older, pre-C4)
What does Convotherm error code E25.0 mean?
The condenser cools the hot exhaust steam before it leaves the oven, and sensor B3 tells the control how hot the condenser is. The control reads B3 through a small circuit and expects a value within a sensible range. When that circuit is open, the control gets no signal at all, as if the wire had been cut. It cannot confirm that the exhaust steam is being cooled, so it stops the steam functions that depend on it and shows E25.0. This is a statement about the wiring and the sensor, not about the temperature itself: the condenser may be perfectly cool. The cause is a broken wire, a plug that has worked loose, or a sensor that has failed. The manual gives one response, to contact customer service, and nothing an operator does at the keypad restores a broken circuit.
Affected models and control systems
Convotherm OES, OEB, OGS and OGB combi ovens (the older, pre-C4 line), from that line's user manual, an English translation of the original edition. It does not state a revision number.
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
- E25.0 on the display
- Steam functions are refused or stop early
- Message appears right after start-up or when steam is requested
- Dry-heat programs may still run
Possible causes
Likely causes — what usually sits behind error code E25.0 on this control. A technician confirms which one it is before any part is replaced.
- Wire to the condenser sensor broken near the exhaust path
- Sensor plug loose or corroded at the connector
- Sensor failed open after years of heat and damp
- Cable pinched when the oven was moved or serviced
Safe checks before calling for service
- Switch the oven off and let it cool before you go near the back of it.
- Do not pull on or move the cables behind the oven, because a loose plug can make the problem worse.
- Restart the oven once and request steam, to see whether the message was a one-time event.
- If E25.0 comes back, stop using steam functions and contact customer service as the manual instructs.
- Write down when the code appears and whether the oven was moved, washed down or serviced just before.
How a technician diagnoses error code E25.0
- Read E25.0 and the history to see whether the code appears at once or only when steam is requested.
- Measure the resistance of sensor B3 at the sensor and compare it with a reference table for its temperature.
- Check continuity of the cable and plug between the sensor and the control board.
- Inspect the connector at the board for looseness, heat marks or corrosion.
- Replace the sensor or the cable section the tests point to.
- Run a steam cycle and confirm the condenser reading looks sensible.
- The sensor circuit is tested with a meter next to line-voltage parts inside the oven.
- The condenser sits in the hot, wet exhaust path, so reaching the wiring can mean exposure to hot water and steam.
- A broken wire and a failed sensor give the same code, and only measurements tell them apart.
How error code E25.0 differs from similar codes
E25.1 is the same sensor with a ground fault instead of an open circuit, and E15.0 is the condenser sensor reading too high.
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
Does E25.0 mean the condenser is too hot?
No. It means the control gets no signal from the sensor, so it cannot tell. E15.0 is the code for a high condenser reading.
Can I keep baking with dry heat?
Often yes, because dry heat does not depend on the condenser, but steam and combi programs may be refused.
Will the code clear by itself?
Only if the cause was a plug that happened to seat again. A broken wire or failed sensor keeps the code until it is repaired.
Need help with Convotherm error code E25.0?
A technician confirms the cause on site and gives you the price in writing before any work starts.