XLT Pizza Oven Error Code Hi Alarm: High Alarm Set Point Exceeded
Hi Alarm means the Hi Alarm set point on the controller was exceeded. The manual's step is a hard reset: unplug the oven for one minute, plug it back in and power on. If the error still exists, contact XLT.
High: the oven passed its configured high limit.
- Code
- Hi Alarm
- Maker
- XLT
- Equipment
- Pizza ovens
- Applies to
- XLT conveyor ovens, gas version H (Standard, World, Australia, Korea) with LUI/OMC controller; the electric version H Parts & Service Manual XD 9007A prints the
What does XLT error code Hi Alarm mean?
The XLT controller allows a separate high-temperature limit, called the Hi Alarm set point, in addition to the baking set point. When the oven goes above that limit, the controller raises Hi Alarm on the LUI, with the HEAT LED flashing and the Alarm LED lit. The manual says only that the Hi Alarm set point was exceeded. It does not give a number, because the limit is whatever has been entered for the oven, and it lists no causes. Its action is the hard reset, followed by a call to XLT at 888-443-2751 if the error is still present. The alarm is easy to confuse with Over Temp, but it works differently. Over Temp compares the oven to the baking set point with a 50F margin and a one-minute delay. Hi Alarm compares the oven to its own separate limit.
Affected models and control systems
XLT conveyor ovens, gas version H (Standard, World, Australia, Korea) with the LUI/OMC controller. The electric version H Parts & Service Manual XD 9007A prints the same table.
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
- Hi Alarm on the LUI display
- HEAT LED flashing with Alarm LED on
- Oven temperature higher than normal
- Burner still firing when the oven should be holding temperature
Possible causes
Likely causes — what usually sits behind error code Hi Alarm on this control. A technician confirms which one it is before any part is replaced.
- Oven probe reading low so the burner keeps heating
- Burner control not shutting off at the set point
- Hi Alarm set point entered too low for the way the oven is run
- Heat building up because airflow in the oven chamber is reduced
Safe checks before calling for service
- Check the temperature on the LUI and compare it with the set point.
- Let the oven cool a few minutes before doing anything else.
- Do the manual's hard reset: unplug the oven for one minute, plug in and power on.
- If Hi Alarm comes back, stop baking and contact XLT or a service company.
- Note the set point, the displayed temperature and whether the Hi Alarm limit had been changed.
How a technician diagnoses error code Hi Alarm
- Read the alarm and compare the displayed temperature with an independent thermometer.
- Check the Hi Alarm set point entered in the controller.
- Check the oven probe reading and wiring for accuracy.
- Check whether the burner shuts off at set point.
- Correct the cause and run the oven through a full heat-up.
- Burner shutoff checks involve gas valves and hot surfaces.
- The Hi Alarm limit is a safety-related setting that should be reviewed by a technician who knows the oven.
- Probe accuracy tests require a meter and a reference thermometer.
How error code Hi Alarm differs from similar codes
Over Temp uses a 50F margin over the baking set point and a one-minute delay. Hi Alarm uses a separate set point, whose value the manual does not state.
Technical reference
- Document
- XLT Gas Oven & XLT Hood Parts & Service Manual (XD 9006A)
- Edition
- 01/05/2026
- Models / control
- XLT conveyor ovens, gas version H (Standard, World, Australia, Korea) with LUI/OMC controller; the electric version H Parts & Service Manual XD 9007A prints the
- Section
- Oven Troubleshooting, p. 28, LUI Service Error Codes
- 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 XLT pizza oven error codes
What temperature triggers Hi Alarm?
The manual does not give a number. It says only that the Hi Alarm set point was exceeded.
Is Hi Alarm the same as Over Temp?
No. They are separate alarms with different rules in the manual.
Is it safe to keep baking?
The oven has passed its own high limit, so let it cool and have it checked before baking again.
Need help with XLT error code Hi Alarm?
A technician confirms the cause on site and gives you the price in writing before any work starts.