Alto-Shaam Combi Oven Error Codes: Troubleshooting and Maintenance Guide

By October 4, 2023March 13th, 2026Resources

Alto-Shaam Combi Oven Error Codes: Troubleshooting and Maintenance Guide

By Pat Finley – Master Certified Lead Technician

Alto-Shaam combi ovens are a powerful and versatile tool used in commercial kitchens, schools, restaurants, and healthcare facilities. These ovens are precision machines that combine steam and convection cooking to produce consistent, high-quality results.

Because they are complex pieces of equipment, proper maintenance and troubleshooting are important. Fortunately, Alto-Shaam’s touchscreen lineup—also known as the CTP series combi ovens—provides built-in error codes that help identify potential problems.

In this guide, we’ll explain several common Alto-Shaam combi oven error codes, what they mean, and when it may be time to schedule professional service.

Common Alto-Shaam Combi Oven Error Codes

Understanding the meaning behind common error codes can help you determine whether the issue is minor or requires professional repair.

Blank or Black Screen

If your Alto-Shaam combi oven display is blank, start with the basics.

Check the following:

  • Make sure the oven is plugged in

  • Verify the circuit breaker is turned on

If both of these appear normal but the screen remains blank, the unit may require professional diagnosis by a trained technician.

Error Code E105 – Low Water Pressure or No Water

Error E105 indicates that the oven is not receiving enough water pressure.

Possible causes include:

  • Water supply turned off

  • Kinked or disconnected water hoses

  • Clogged water filters

  • Reverse osmosis system malfunction

Start by checking the water supply and hoses. If the problem persists, a technician may need to inspect the system.

Error Code E109 – High Limit Tripped

The E109 error code means the oven’s high-limit safety switch has been triggered.

You can try resetting the high-limit switch. If the oven resumes normal operation, the issue may be temporary.

However, if the error returns, it may indicate:

  • Stuck electrical contactors

  • Shorted heating elements

  • A failing high-limit switch

These issues should be inspected by a professional service technician.

Error Code E2 – Control Compartment Overheating

Error E2 means the oven’s control compartment temperature is too high.

Common causes include:

  • Failed cooling fan

  • Blocked cooling fan intake

  • Improper installation near heat sources

This issue should be addressed quickly to avoid damage to expensive electronic components.

Error Code E100 – Maintenance Reminder

Error E100 is not necessarily a malfunction. Instead, it serves as a maintenance reminder.

To resolve it:

  • Navigate to the maintenance reminder screen

  • Review which maintenance tasks are overdue

Regular maintenance helps prevent larger equipment problems later.

Error Codes E88 and E89 – Gas Ignition Failure

Error codes E88 and E89 indicate that the oven’s burner failed to ignite.

Check the following:

  • Gas supply is turned on

  • Gas hoses and quick connections are secure

If the unit still does not ignite after restarting, contact a service technician to diagnose the issue.

Error Codes E5 and E6 – VFD Communication Failure

Errors E5 and E6 indicate communication failures between the Variable Frequency Drive (VFD) and the control board.

The VFD controls blower fan speed and rotation, which is essential for proper oven performance.

These errors typically require professional diagnosis.

Error Codes E7 and E8 – VFD Operational Errors

Errors E7 and E8 are also related to the Variable Frequency Drive system.

Technicians often use these codes along with internal LED indicators to determine the exact problem.

If these errors do not clear, schedule service with a trained technician.

Best Practices When an Error Code Appears

Alto-Shaam combi ovens can display hundreds of different error codes.

When you encounter one:

  • Write down the error code

  • Take a photo of the display

  • Share the information with your service technician

Providing the exact code helps technicians diagnose the issue faster and get your oven back up and running.

Schedule Alto-Shaam Combi Oven Service

If your Alto-Shaam combi oven is displaying persistent error codes or not operating properly, professional service may be required.

General Parts provides factory-trained technicians for Alto-Shaam combi oven repair and maintenance.

Call 1-888-498-1238 or request service online to schedule a technician and keep your kitchen running smoothly.