Lincoln Aperion 24 Oven Blower UV: 0x04 Low Line Voltage
Upper Blower UV: 0x04 or Lower Blower UV: 0x04 means the blower drive sees line voltage below 151 VAC. Ensure the input voltage is within specifications. The alarm recovers automatically above 174 VAC.
Medium: the blower drive stops until the supply recovers.
- Code
- Upper/Lower Blower UV: 0x04
- Maker
- Lincoln
- Equipment
- Pizza ovens
- Applies to
- Aperion 24 UI
What does Lincoln Upper/Lower Blower UV: 0x04 mean?
The blower motor drive monitors the voltage it receives. If the line voltage falls below 151 VAC, the drive reports undervoltage, and the screen shows "Upper Blower UV: 0x04" or "Lower Blower UV: 0x04". The drive LED blinks red and yellow, 0.25 seconds on and off. The manual lists one cause, line voltage less than 151 VAC. The alarm recovers automatically once the voltage rises above 174 VAC, so the gap between 151 and 174 VAC keeps the alarm from flickering on and off. The remedy is to ensure the input voltage is within specifications. This is mainly a supply issue, such as a sagging line, a weak breaker connection, an overloaded circuit or an oven wired for the wrong voltage. Because the drive recovers by itself, the alarm may come and go with the kitchen's other loads, and an operator may only see it at busy times such as the lunch rush, when ovens, fryers and dish machines all run together. Write down the time each alarm appears, since that pattern is the best clue for the electrician.
Affected models and control systems
Lincoln's electric Aperion 24 (2424E, 60 Hz) with easyTouch, as reported by either blower drive.
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
- Blower UV: 0x04 on the touchscreen
- Drive LED blinking red and yellow
- Blower stopping and starting by itself
Possible causes
Listed in Lincoln's documentation
- Line voltage less than 151 VAC
Other likely causes — what usually sits behind Upper/Lower Blower UV: 0x04 on this control. A technician confirms which one it is before any part is replaced.
- A loose lug on the oven's breaker or terminal block that drops voltage under load
- A circuit shared with other heavy equipment that sags when they start
Safe checks before calling for service
- Note whether the alarm appears when other large equipment starts.
- Make sure the oven's breaker is fully on.
- Do not open the electrical compartment.
- Tell the technician the times it appeared and what else was running.
How a technician diagnoses Upper/Lower Blower UV: 0x04
- Read the alarm and the drive LED pattern.
- Measure line voltage at the oven's supply terminals with the oven running.
- Check lugs and connections for heat damage.
- Trace the circuit for shared loads or an undersized feed.
- Replace the drive only if the line voltage is good and the alarm persists.
- Line voltage is measured on live 208-240 V terminals.
- Finding a sagging supply may involve the building's panel.
- Heat-damaged lugs need correct repair.
How Upper/Lower Blower UV: 0x04 differs from similar codes
UV 0x04 is low line voltage; OV 0x06 is high line voltage, with its own recovery level.
Technical reference
- Maker documentation
- Lincoln owner support
- Edition
- LIN_EO_SM_IMPAPERION2424_4607818 07/21
- Models / control
- Aperion 24 UI
- Section
- Section 5 Troubleshooting, UI Alarm Messages, pp. 28-29
- 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 Lincoln pizza oven error codes
Will UV clear by itself?
Yes, it recovers automatically above 174 VAC.
Is the drive itself the problem?
Probably not; the cause the manual lists is low line voltage, so the supply is checked first.
What voltage is too low?
Below 151 VAC.
Need help with Lincoln Upper/Lower Blower UV: 0x04?
A technician confirms the cause on site and gives you the price in writing before any work starts.