When a refrigerator can’t properly ventilate – usually due to a buildup of dust that blocks the exhaust fan’s vents – heat can’t dissipate, thus the whole fridge heats up and can’t cool itself off. This leads to the fridge struggling to maintain internal temperature, and if the heating issue isn’t addressed, the motor may burn out. When overheating issues arise, unplug the unit from the wall, pull the fridge back a couple of feet and tilt the unit back to gain access to the underside -- you may need assistance with this step. If there’s a substantial accumulation of dust and debris, pull it out of the vent and use canned air to blast hard to reach areas.
If the bulb isn’t coming on when you open the fridge, chances are one of three things are to blame: the bulb is burned out, the switch is stuck or the light fuse is spent. When replacing the bulb, pop off the bulb cover, don some gloves and unscrew or slide out the bulb. Reverse these steps to replace the old one with a new one. If the switch is stuck, meaning it’s depressed and can’t pop out fully to disengage the switch, try pressing a butter knife down into the switch to get it to pop out. For faulty or spent wiring, you’ll need to contact a repair person or the store where you purchased the unit for warranty information.
Another problem is when the fridge doesn’t contain enough chemical coolant to cool down food properly or simply doesn’t have enough to cycle through a fridge of a larger size. The good news: all the fridge needs is more coolant; the bad news: it’s unlawful in many jurisdictions for unlicensed people to handle chemical coolants. A call to your local refrigeration repair person to schedule a house call should help out.
Low levels of coolant could be a result of a coolant leak. Most modern fridges use gas coolants that cycle to keep the contents at a pre-selected temperature setting. A leak reduces this efficiency. A look under or behind the refrigerator helps pinpoint the location of the leak – look for nicks or frays in the hoses or at the connection points. Patch kits exist to close up and repair leaks, but these are meant as quick fixes; you'll still need to call a repair person.