Alto-Shaam Combi Oven Error Code E02: Control Temperature High
E02 Control Temperature High means the relay board inside the oven has passed 176 F (80 C). Press the Start icon to acknowledge it and make sure nothing blocks the air around the oven's cooling intake. If E02 returns, a technician should check the cooling fan and the relay board.
Medium: the oven can try to resume, but overheating of the relay board can stop it again.
- Code
- E02
- Maker
- Alto-Shaam
- Equipment
- Combi ovens
- Applies to
- Combitherm CT PROformance (CTP) and CT Classic (CTC); Combitherm CT Express / ESi / CCi (older 4-10 and 4.10 units; boiler or generator electric/gas)
What does Alto-Shaam error code E02 mean?
Behind the control panel sits a relay board that switches the oven's heaters, valves and motors. It makes its own heat, and the oven moves air across it with a cooling fan so the board stays well below damage level. The control watches the board temperature, and when it reads above 176 F (80 C) it posts E02 Control Temperature High. The reading can climb because the fan has stopped or slowed, because the air intake that feeds it is blocked, or because the board itself is failing and running hot. Pressing Start acknowledges the message and the oven then tries to return to normal operation, but if the cooling problem remains the board heats up again and the code reappears. In a busy kitchen, grease and lint on an intake are the usual way airflow is lost, which is why this code often shows up after a long, hot service.
Affected models and control systems
Combitherm CT PROformance (CTP) and CT Classic (CTC) electric and gas combis, models 6-10, 10-10, 7-20, 10-20, 20-10 and 20-20. The older CT Express manual carries E02 under the same wording.
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
- E02 Control Temperature High on the display
- Code returning after a long run of hot cooking
- A fan that sounds slower or quieter than usual near the control area
Possible causes
Listed in Alto-Shaam's documentation
- Cooling fan malfunction
- Cooling fan air intake blocked
- Relay board malfunction
Other likely causes — what usually sits behind error code E02 on this control. A technician confirms which one it is before any part is replaced.
- Grease and lint packed into the intake grille from a kitchen with heavy fryer use nearby
- Oven installed too close to a wall or a heat source so the cooling air is already warm
Safe checks before calling for service
- Press the Start icon once to acknowledge E02.
- Look at the outside air intake and vents on the oven and clear any visible lint, paper or boxes without opening a panel.
- Confirm there is clear space around the oven as marked in the installation notes.
- If E02 returns after the oven has cooled, write down how long it had been running and call for service.
How a technician diagnoses error code E02
- Read the code and note how long the oven had been running when it appeared.
- Inspect the cooling fan for rotation and the air path for blockage.
- Check the fan's supply voltage and wiring with a meter.
- Measure the relay board temperature in operation to compare with the 176 F (80 C) limit.
- Replace the fan if it is weak or dead, and replace the relay board only if it still overheats with good airflow.
- Reaching the fan and relay board means opening the control compartment with live 208-240 V wiring.
- Judging whether the board is overheating or just poorly cooled takes a meter and a temperature reading.
- A failing board can damage the loads it switches, so it should not be run to see what happens.
How error code E02 differs from similar codes
E02 is a board temperature code; the other E-numbers in this family name a probe or a motor, so the cause lies in airflow rather than in a cooking temperature.
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); Combitherm CT Express / ESi / CCi (older 4-10 and 4.10 units; boiler or generator electric/gas)
- 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
Does E02 mean the cooking chamber is too hot?
No. It refers to the relay board temperature, not the cavity.
Can I keep using the oven after I press Start?
The oven tries to return to normal operation, but if the board is still running hot it will stop again. Clear the intake and keep an eye on it.
Will E02 clear on its own?
After the board cools it may, but without fixing the fan or blocked air it will come back.
Need help with Alto-Shaam error code E02?
A technician confirms the cause on site and gives you the price in writing before any work starts.