Refrigerator not cooling but the light is on: what to check, from the door seal to the compressor

• Switch off the MCB and unplug the appliance before checking anything.
• Make sure your hands and the floor are dry.
• Never puncture, cut or recharge the refrigerant lines; that work is for a certified technician only.

You can leave it plugged in for steps that only involve looking or turning the temperature control. As soon as your hands go behind or under the refrigerator, unplug it first.

The interior light and the cooling system work independently. The light comes on whenever the door opens, as long as power reaches the plug. Keeping the inside cold depends on other parts: the compressor pumping refrigerant, the fan moving cold air and the condenser releasing heat into the room. A working light therefore confirms only one thing: the refrigerator has power. LG Indonesia's help page starts with the opposite case: if the light does not come on when you open the door, first check that the power cord is plugged in properly.

The most common causes are simple. LG lists three groups: a temperature set too warm, airflow blocked because the refrigerator is packed too full or the vents are covered, and warm air getting in because the door does not close completely. Samsung adds the location: direct sunlight, a nearby heat source, or a refrigerator pushed so close to the wall that air cannot reach the condenser. Only once all of those are ruled out is it worth suspecting a fault in the cooling system.

1. Temperature setting. If the refrigerator compartment does not feel cold enough, LG recommends a setting between 1°C and 3°C; at 5°C or 6°C it will not feel cold enough. On a refrigerator with a numbered dial, turn it toward the colder number given in the manual, then wait a few hours before judging.
2. Contents and vents. Keep the refrigerator no more than 70% full so cold air can circulate, and move any food that covers the vents on the back wall of the main compartment or the freezer.
3. Door and door seal. Make sure the shelves sit correctly, the bottles in the door rack stand upright, and nothing sticks out and keeps the door from closing fully. Clean the door gasket with a toothbrush and soapy water as the Sharp manual advises, then dry it. A seal that is torn or no longer seals against the cabinet is a job for a service technician.
4. Location. Keep the refrigerator out of direct sunlight and away from the stove. For the Sharp SJ-U43P, the manual gives a gap of 50 mm or more, but less than 75 mm, between the back of the refrigerator and the wall. Other models list their own figures in the manual.
5. Dust at the back. With the plug pulled, brush or vacuum the dust off the back and the condenser grille, without pressing on the tubes.
6. Frost. On a model without automatic defrost, the Sharp manual says to defrost once the frost on the evaporator is 5 mm thick. Unplug the refrigerator and let the frost melt with the door open; never chip the ice off with a knife or anything sharp.
7. Give it time. After all the steps, switch it back on and let it run without opening the door too often. For a refrigerator that was just installed, moved or repaired, LG says it takes about two to three days to reach its working temperature.

A refrigerator is designed for a given range of room temperatures, printed as the climate class on its rating plate. The Sharp manual describes class T for room temperatures up to 43°C; outside its class range, a refrigerator may not keep the inside cold. In a small, closed-in kitchen right next to the stove, the condenser has to work harder, so moving the refrigerator to a more open spot can matter more than turning the temperature dial.

Mains voltage is worth watching too. The manual for the Sharp SCH-210FS cooler says the unit can run on 187 V to 242 V and recommends a voltage stabilizer in areas where the voltage often rises and drops. If the interior light dims or flickers when other appliances switch on, note the time and tell the technician. The same manual asks for a pause of about seven minutes before switching the unit on again after it was turned off. So do not keep unplugging it and plugging it back in while you try things.

Humid air makes condensation form easily on the outside of the cabinet and on glass doors. The Sharp manual says condensation in the rainy season does not affect normal use and can simply be wiped off. Condensation inside the refrigerator is different: it means outside air is getting in, usually around the door.

Some household refrigerators use a flammable refrigerant; the Sharp SJ-U43P manual, for example, names R600a (isobutane). The rating plate shows which refrigerant your refrigerator uses. Because of the flammable refrigerant, the manual forbids letting pointed objects touch the cooling system behind and inside the refrigerator, and forbids mechanical tools to speed up defrosting. If the cooling system is damaged, it says to open the windows without touching the socket or lighting a flame. A refrigerator with automatic defrost never needs defrosting by hand, so thick ice on such a model means something is not working.

The Sharp manual also asks you to plug the refrigerator straight into the wall socket, without an extension cord or adapter plug, and to unplug it before cleaning. A damaged power cord has to be replaced by an approved service agent, because it needs a special cord.

Stop checking it yourself and contact the authorized service center for your refrigerator's brand if:

• the refrigerator is still not cold two to three days after the setting, door, contents and location are all correct. LG suggests a simple test: put water in the freezer and in the main compartment, then call a technician if no thin ice forms or the water does not get cold;
• you cannot hear the compressor running at all, or it starts and stops again and again;
• you smell burning from the refrigerator or the socket (pull the plug at once if it is safe to do so);
• you suspect a leak in the cooling system, such as a gas smell or frost that keeps building up on a model with automatic defrost;
• the door seal is torn, a hinge has sagged, or the power cord is damaged.

Repairs to the refrigerant system, including finding a leak and recharging the refrigerant, are work for a certified technician. A socket that is loose, hot or scorched should be checked by a qualified electrician, not worked around with an adapter.