A shock every time you open your refrigerator door means something is off with the grounding of the refrigerator or that dry winter air is getting the better of your kitchen. Troubleshoot your fridge to solve the problems. While newer refrigerators with advanced capabilities might be more likely to give you shocks than simple or old models, any refrigerator can cause static electricity if the right circumstance arises.
Winter brings dryer air and static electricity. If your refrigerator's static electricity is seasonal, increasing the humidity in your home can help. If you experience static electricity in seasons with higher humidity, this might be a shock that indicates another problem. Infrequent shocks happen when static charges build up in clothes, shoes and other material. They aren't of much concern.
Refrigerators with computer chips that control ice makers, defrost setting and temperature are more sensitive to static electricity. If these models are not properly plugged in, you can experience a shock that feels like static electricity. If your fridge's cord has frayed so that a metal wire is touching metal somewhere, you will get a similar shock.
For seasonal problems, use a humidifier in the kitchen to increase the moisture in the air and cut down on static electricity naturally. Take preventative action by carrying a metal coin in your pocket and touching the coin to ground yourself before you touch the refrigerator. You won't get shocked when you're grounded. Synthetic fibers are more sensitive to static electricity, so wear natural wools, cottons and other fabrics to reduce the shock.
Troubleshooting Other Problems
Check your refrigerator manual to see what type of outlet the manufacturer recommends. If your refrigerator needs a 3-prong, grounded and polarized outlet and you aren't using one, that's probably the cause. Use a circuit tester to check whether the outlet is grounded. Switch to a proper outlet, or plug the fridge cord into a surge protector to cut down on shocks. If you see wear and tear on the cord, replace it to solve your problem.