Seasonal shutdown and restart of commercial refrigeration

Shut down or keep running?

For a closure of a week or two, it is often simpler to keep a unit running with a light load, provided someone checks it and the power is reliable. For longer closures, shutting down saves energy and wear. If the site may lose power or nobody will visit, empty and shut down — a full unit that fails unattended is the worst outcome.

Shutdown step by step

• 1. Run stock down in the final days so there is little to move or discard.
• 2. Empty the unit completely, including drawers and door racks.
• 3. Switch off and unplug, or switch off at the MCB.
• 4. Defrost fully. Leave doors open and let ice melt naturally; mop meltwater and clear the drain.
• 5. Clean and sanitise the interior, shelves, gaskets and drain path. Clean the drip tray.
• 6. Clean the condenser coil now, while you have time, so the unit is ready for restart.
• 7. Dry everything completely — interior, gaskets, drain line, tray.
• 8. Prop the doors or lid open a few centimetres so air circulates. A closed, dark, damp cabinet grows mould within weeks.
• 9. Coil the power cord, lock castors, and cover the unit loosely with a breathable sheet, not plastic wrap that traps moisture.

Where and how to leave it

• Keep units upright, in the same place if possible, so they do not need moving at restart.
• Store them dry, off the floor if there is any flood risk, and away from direct sun.
• Protect against rodents and cockroaches: clean under and behind the unit, remove cartons, and set monitoring traps nearby.
• In coastal sites, wipe external steel and leave a note to inspect for corrosion at restart.

Before restarting

• Inspect the power cord and plug for damage, including rodent chewing, and check the socket and earthing.
• Look into the machine compartment for nests, debris and droppings. Clean with the power off.
• Clean the condenser if dust has settled.
• Check gaskets are soft and seat properly; long storage with doors propped open can distort them slightly — closing the door for a few hours usually lets them recover.
• If the unit was moved or tilted, let it stand upright for the rest period the manufacturer recommends before switching on.

Restart and pull-down

• 1. Close doors and switch on with the cabinet empty.
• 2. Listen for the compressor and fans starting normally. New buzzing, clicking or a compressor that tries and fails to start needs a technician.
• 3. Let the cabinet reach its set temperature, then watch it run for several hours or overnight. It should cycle on and off normally.
• 4. Check the temperature with a separate calibrated thermometer, not only the display.
• 5. Load gradually, starting with already chilled or frozen stock.

Common problems after long storage

The usual issues are rodent damage to wiring, a seized condenser or evaporator fan, a controller or display fault from moisture, and gaskets that have stuck to the frame. Compressors that stood unused can occasionally struggle to start. Booking a technician's check before the season reopens, rather than on the first busy day, gives time to fix these.

Safety notes

Isolate power before cleaning or inspecting. Propped-open units can be a hazard to children or animals at unattended sites — prop doors only a few centimetres or remove them if the site is accessible. Units with hydrocarbon refrigerants should be stored where ventilation is adequate; never store them near open flames, and leave any refrigeration repair to a technician trained for flammable refrigerants.