During an outage keep the walk-in door shut, write down the time, and probe the food instead of opening the box. When power returns, check the outdoor unit for water and debris, let the system restart normally, and watch it come down to temperature. Call a technician if it does not start, trips, or hums after the restart.
Storms are a fact of life in the Pine Belt. An EF4 tornado crossed the Hattiesburg area on February 10, 2013, and an EF3 tornado on January 21, 2017 left about 10,000 people without power. Hurricane Ida in 2021 brought flooded roads and widespread blackouts, and severe storms in March 2026 cut power across nearby counties. For a walk-in, an outage is two problems: the food warms while the power is off, and the equipment can be hurt when the power comes back.
During the outage
- Keep the door closed. A closed, full walk-in holds cold far longer than one that keeps being opened. Decide what you need before you open it once.
- Write down the time. Note when the power went out and the temperature at that moment. If you can, log the temperature at regular intervals from a probe in a container, not the air.
- Protect the most perishable food first. If the outage will be long, plan to move meat, seafood, dairy and prepared food to coolers with ice. See the food-safety guide for the time limits and what to keep.
- Turn off big loads if you can. Switching off the unit at the disconnect prevents a sudden start with an unstable supply when power flickers on and off.
- Do not connect a generator to building wiring yourself. Backfeeding can kill line workers and destroy equipment. A generator should be connected only through a proper transfer switch installed by an electrician.
What the outage and the return of power can do to the equipment
| Risk | What happens |
|---|---|
| Voltage surge on return | Can damage capacitors, contactors, control boards and compressor windings |
| Rapid on-off flicker | Compressor tries to start against high pressure, overheats and trips |
| Flooding at the outdoor unit | Water in the electrical section or wet wiring, possible shorts |
| Debris on the condenser | Blocked airflow and bent fins on restart |
| Frozen coil or drain after a long shutdown | Ice forms when the box warms and refreezes wet parts |
| Roof or wall leaks into the box | Water on the ceiling panels or controls |
Before you restore power
- Look at the outdoor unit from a safe distance. Is there standing water around it, broken branches, or sheet metal blown against it?
- Check the electrical disconnect and panel for water. If wet, do not switch it on.
- Clear debris off the condenser without pushing it into the fins.
- Look at the roof and the box ceiling for water intrusion.
- If the power went out and came back several times, wait until it has been steady for a few minutes.
The restart
Many controllers include a delay that keeps the compressor off for a few minutes after power returns, so pressures equalize before it starts. If yours does not, waiting several minutes yourself before switching the unit back on is a reasonable habit. Then stay nearby and watch. The outdoor fans should spin, the compressor should start smoothly, the inside fans should run, and the box temperature should begin to fall. A compressor that hums without starting, a breaker that trips, or a burning smell means switch it off and call. Do not keep trying.
After the restart
- Watch the temperature come down. Compare the display with a separate thermometer. A box that does not start dropping within a reasonable time needs attention.
- Check for ice. A warm box that refroze can leave frost or ice on the coil and drain. See freezing up and defrost repair.
- Listen for new noises. Squeals, rattles or a loud hum after a surge can point to a damaged motor or capacitor.
- Look for delayed damage. Parts stressed by a surge can fail days later. Note the date of the event so a technician can connect the dots.
- Record everything. Times, readings, what you discarded, and any repairs. It helps with an inspector or an insurance claim.
Preparing before the next storm
- Write a short outage plan and post it near the door.
- Keep probe thermometers and spare coolers accessible.
- Ask an electrician about surge protection for the condensing unit and about a generator connection through a transfer switch.
- Keep the area around the outdoor unit clear.
- Book the spring inspection described on the maintenance page, so weak parts are replaced before storm season.
When to call a technician
- The compressor will not start or hums after the restart.
- A breaker trips again after you reset it once.
- You saw water in the electrical section or around the unit.
- The box is not falling toward temperature after a reasonable time.
- You smell burning or see scorched wiring.
Send details on the contact page, and say when the outage began and ended.
Questions about outages and storms
Should I turn the walk-in off during an outage?
Switching off the disconnect stops an unstable supply from restarting the compressor repeatedly. Turn it back on once power has been steady. Keep the door closed either way.
Can a surge damage a walk-in without an obvious sign?
Yes. Capacitors and control boards can be weakened and fail later. If a storm passed through and a part fails soon after, mention the storm to the technician.
Is a generator worth it for a walk-in?
For a busy kitchen or store in a storm-prone area, it can be. It must be sized for the compressor start current and connected through a proper transfer switch by an electrician.
How do I know the food is still safe after a long outage?
Probe the food, check your log for how long it was above the limit, and use the guidance in the food-safety guide. If you hold a permit, follow your inspector's direction.