If the defrost drain system is plugged, it can cause several symptoms. Once the drain pan freezes over, the water can end up in several places. In a Side-by-Side, it can become an ice sheet in the bottom of your freezer compartment. I have even seen crisper drawers cracked and broken by ice expansion, and wire drawers frozen into a waterfall made of ice. (An icefall?)
Even after the defrost drain system is overwhelmed and frozen over, the defrost water still has to go somewhere, right?
So in a top freezer refrigerator, it will start dripping from the ceiling of the fridge compartment, then run down to the bottom, eventually ending up on the kitchen floor.
In a side-by-side or bottom-freezer, water will pool and freeze at the bottom of the freezer, and eventually start showing up on the floor in front of the refrigerator.
We gotta make sure that defrost drain is running clear.
First, locate the defrost drain pan, and the hole in it.
On BOTTOM-EVAP FREEZERS, it is beneath the evaporator, either directly in the center of the evaporator, or towards the back wall of the freezer. You have to lift one end of the evaporator (GENTLY!) to access it. You can prop it up with something not sharp, like a wooden spoon, while you clear the drain.
On BACK-EVAP FREEZERS, (including SIDE-BY-SIDES and BOTTOM-FREEZER units) there will be a pan with a drain hole in it, directly beneath the evaporator. The pan will probably be full of ice.
Some back-evap models actually have small heaters attached to the underside of the drain pan. The heater prevents the defrost water from re-freezing and clogging the defrost drain hole when it hits the cold defrost drain pan. If the heater is
not working properly, it may have the same effect as a clogged defrost drain, a buildup of ice.
These heaters are generally used where the defrost heater may not be mounted close enough to the drain pan to prevent it from refreezing the drainage. These drain pan heaters are a much lower wattage than the defrost heater and run a bit cooler; when operating, they will feel warm to the touch.
If you have a back-evap model, check the defrost drain pan for a heater. To find it, look for its two power leads. If there is a heater, check it for continuity with a Multimeter
CLICK HERE if you don't have, or know how to use, an ohmmeter.
Replace it if it is bad. They are usually held to the pan by spot-welded tubes
or clamping plates, or by super-sticky aluminum tape.
Any ice or water in the drain pan and drain must be removed and/or melted and the drain cleared.
Labels can fall off frozen food and get into the drain, peas and corn can fall out of freezer bags, lots of stuff could be clogging your drain tube. Any icky debris clogging the drain tube must be removed.
The fastest way to do this is to melt the ice with a blow dryer and to blow the drain clear with a pan of hot water and a syringe-type turkey baster.
Better yet, if you have the time and patience, leave the fridge open for a few hours and let the ice melt naturally. You can blow a fan or space heater into the open freezer to speed up the process. Large, loose chunks of ice in the evaporator compartment can be removed by hand, but make sure there aren't any electrical wires frozen into the chunks of ice before you start pulling on them.
If there is a removable drain tube or trough running along the roof of the food compartment to the back of the fridge, remove it so you can get all the ice.
As you go along, keep sucking out the excess water (now cold from melting ice) with your turkey baster and put it into an empty pot. This will prevent it from diluting the incoming hot water. It will also prevent it from ending up on your kitchen floor.
Any water that gets through the drain hole will end up in the drain collection pan beneath your refrigerator. Continue blowing hot water into the drain hole until you hear it running into the collection pan beneath your fridge. Give it a few extra blasts of hot water to make sure you get all the ice and any debris.
Using your turkey baster, empty this collection pan now and then. It will prevent the pan from overflowing onto the floor. If it is too inconvenient or messy to do so, don't worry about it. The water will evaporate eventually.
Sometimes an ice buildup can block, or even damage the evaporator fan. Let's make sure it works.
If there is anything blocking the fan, clear it out of the way. Press the door switch. The fan should run.
If it still does not run, either the fan motor or the door switch is bad. Or both.
Fixing the Evap Fan
TESTING AND REPLACING THE EVAPORATOR FAN MOTOR AND SWITCH
You can use a voltmeter to check for voltage across the fan motor leads (with the door switch pressed, of course.) If you have voltage across the fan motor leads, but it is not running, the fan motor is bad. Replace it.
If you don't have a voltmeter, or don't know how to use one, you have a couple of choices. CLICK
If you don't have voltage to the fan motor, the door switch might be bad. Take power off the fridge and pry out the door switch. You might have to destroy it to get it out. Check for voltage to the switch. If the switch is bad, replace
REPLACING THE EVAPORATOR FAN MOTOR
In replacing the fan motor, you must make sure that the rotation of the new fan motor is the same as the old one. The easiest way to do this is to look for the shading poles on the old fan motor.
If they are on opposite corners from the ones on the new fan motor core, it is a simple enough task to reverse the new rotor in its core. Carefully remove the bearing cage screws and simply turn the rotor around so the shaft sticks out the other end of the motor.
Get One-On-One Repair Help from a Real, Live Human Being.