Alto-Shaam Combi Oven Error Code E27: B10 Point 2 Probe Failure
E27 B10 - Point 2 - Core Temperature Probe Multipoint Fault means sensing point 2 of the multipoint core probe, B10, is defective or disconnected. Press the Start icon to acknowledge it, and call if it returns.
Low: only multipoint probe cooking is affected.
- Code
- E27
- Maker
- Alto-Shaam
- Equipment
- Combi ovens
- Applies to
- Combitherm CT PROformance (CTP) and CT Classic (CTC)
What does Alto-Shaam error code E27 mean?
Each sensing point of the multipoint core probe B10 has its own signal, so the control can tell which one has gone wrong. When the second point is open, shorted or missing, the control posts E27 B10 - Point 2 - Core Temperature Probe Multipoint Fault. A healthy probe is required for programs that cook to a core temperature, because the control needs every point to trust the reading. The manual lists the same two causes as for the other points: a failed probe or miswired or disconnected wires. Pressing Start acknowledges the message and the oven then tries to return to normal operation, but a cooking run that uses the probe repeats the check. A message for point 2 alone suggests a single failed sensor or a broken line, while several messages together suggest a damaged cable or a loose plug. The manual for the CT Express lists E27 with a different meaning.
Affected models and control systems
Sizes 6-10 through 20-20 of the CT PROformance and CT Classic, electric and gas. A CT Express showing E27 has a different problem, described on its own page.
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
- E27 Point 2 message on the display
- Multipoint probe program failing to run
- Probe plugged in but one reading missing
Possible causes
Listed in Alto-Shaam's documentation
- B10 probe malfunction
- B10 probe miswired or wires disconnected
Other likely causes — what usually sits behind error code E27 on this control. A technician confirms which one it is before any part is replaced.
- A weak connection in the plug that affects only the second sensing line
- Probe handle end damaged by being pulled out by the cable
Safe checks before calling for service
- Press the Start icon once to acknowledge E27.
- Remove the probe and plug it back in until it seats fully.
- Check the cable for kinks, cuts or flattening.
- If E27 returns, say whether it appears alone or with other point messages, then use time-based cooking.
How a technician diagnoses error code E27
- Read the code and see whether other point messages appear.
- Inspect the probe and plug; clean and reseat.
- Meter the second sensing line from plug to sensor.
- Check the receptacle and wiring for continuity back to the board.
- Replace the probe only after the failed line is confirmed.
- The sensing lines are tested with a meter and the probe disconnected.
- The receptacle is wired to the control board inside the oven.
- A wrong reading could leave food undercooked.
How error code E27 differs from similar codes
E26 is point 1, E28 point 3 and E29 point 4 of B10, while E22 refers to the probe as a whole; CT Express uses E27 for an element too hot message.
Technical reference
- Maker documentation
- Alto-Shaam owner support
- Edition
- MN-35949 Rev 08 03/22
- Models / control
- Combitherm CT PROformance (CTP) and CT Classic (CTC)
- Section
- Error Codes, pp. 25-31
- 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 Alto-Shaam combi oven error codes
Is E27 a separate problem from E26?
It is the same probe, but a different sensing point.
Do I need a new probe for E27?
Only if cleaning and reseating do not clear it.
Why does the oven name a point number?
So the technician knows which sensing line of B10 to test first.
Need help with Alto-Shaam error code E27?
A technician confirms the cause on site and gives you the price in writing before any work starts.