Alto-Shaam Combi Oven Error Codes E220-E228: Lower VFD Errors
E220 to E228 are the lower fan drive messages on roll-in ovens: E220 under voltage, E221 over voltage, E222 overheating, E223 motor over current, E224 current peak, E225 EEPROM, E226 over current, E227 short circuit and E228 voltage error. Press the Start icon to acknowledge, and note the exact number for the technician.
High: the lower fan drive is reporting a problem and the lower fan may not run.
- Code
- E220-E228
- Maker
- Alto-Shaam
- Equipment
- Combi ovens
- Applies to
- Combitherm CT PROformance (CTP) and CT Classic (CTC) roll-in models
What does Alto-Shaam error code E220-E228 mean?
These nine codes are the lower-drive version of E210 to E218. The lower variable frequency drive, or VFD, runs the lower convection fan on roll-in ovens, and it reports what it finds: E220 to E228 (Lower VFD under voltage, over voltage, overheating, motor over current, current peak, EEPROM error, over current, short circuit, voltage error). The number tells the technician which condition was found. Under and over voltage point to the supply, overheating to cooling air, the over-current and short circuit codes to the motor or its wiring, EEPROM to the drive's memory, and E228 to a voltage jumper in the wrong position. The manual's causes are a possible lower VFD malfunction, a blocked fan wheel for E223, an overheat condition, defective high limit switch or cooling fans for E222, and a jumper for E228. Pressing Start acknowledges the message and the oven tries to return to normal operation.
Affected models and control systems
Roll-in CT PROformance and CT Classic combi ovens with two fan drives; a table-top oven reports the same conditions on its single drive as E210 to E218.
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
- One of the E220 to E228 messages on the display
- Lower fan stopping or not starting
- Upper fan continuing to run
Possible causes
Listed in Alto-Shaam's documentation
- Possible lower VFD malfunction
- Blocked fan wheel (E223)
- Overheat condition, defective high limit switch or cooling fans (E222)
- Voltage jumper in wrong position (E228)
Other likely causes — what usually sits behind error code E220-E228 on this control. A technician confirms which one it is before any part is replaced.
- Lint packed in the lower drive's cooling path in a tight roll-in cell
- A lower motor cable chafed at the base of the oven
Safe checks before calling for service
- Press the Start icon once to acknowledge the message.
- Write down the exact number: E220, E221, E222 and so on.
- Check that the intake at the base of the oven is clear.
- If it returns, give the technician the number, the time and what the oven was doing.
How a technician diagnoses error code E220-E228
- Read the exact code and the lower drive LED blink code.
- Match the code to the cause: supply, cooling, load, memory or jumper.
- Check the lower fan wheel by hand for blocking, and the cooling fans and high limit.
- Check the voltage jumper against the rating plate.
- Replace the lower VFD or motor only after the tests.
- The lower drive sits low in the oven, near moisture and 208-240 V.
- Some codes require reading drive measurements under power.
- Each code points to a different test.
How error code E220-E228 differs from similar codes
E210 to E218 are the same messages for the table-top or upper drive; E220 to E228 apply only to the lower drive of roll-in ovens.
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) roll-in models
- 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
What is the difference between E222 and E212?
E222 is the lower drive overheating; E212 is the upper drive.
Do all nine codes need a technician?
Yes, though the cause differs by number.
Can I run the oven on the upper fan?
The control will not continue normally with the lower drive in error.
Need help with Alto-Shaam error code E220-E228?
A technician confirms the cause on site and gives you the price in writing before any work starts.