How long after a power cut will a fridge stay in alarm mode?

It depends on how warm the cabinet and stock got during the outage, but it is normal for a Unifrost commercial fridge controller to show a flashing temperature and/or a HI alarm for a while after power returns while it pulls back to setpoint.

Use these practical checks to judge if it is normal recovery or not:

Allow recovery time with the door closed: keep openings to a minimum and let the unit stabilise.

Watch the trend, not the number: if the displayed temperature is steadily dropping, the alarm is typically just power cut recovery.

Verify the basics: confirm the plug has power, the controller is not in OFF, and the fans and compressor sound like they are running.

Escalate if it does not improve: if the temperature is not coming down after a reasonable period with the door closed, or the alarm returns repeatedly, treat it as a fault condition and move to troubleshooting or service.

Read the full guide: Understanding Your Unifrost Commercial Fridge Controller: Power Cut Recovery and Alarm Management.