Kelly's Korner - More Mysteries of the Refrigerator

Hey, All,

A couple of weeks ago, I gave you a very simplified explanation of how a refrigerator works, with a promise of more to come.  Well, here it is.

If any of you out there remember spending hours melting, chipping and cleaning ice out of your freezer, you are probably thanking the deities for the development of the frost free systems in our refrigerator/freezers because with the help of technology, we don't have to do that anymore.

As learned in our last session, the coolant (which is very cold now) flows through the evaporator and absorbs the warm air in the freezer.  Because the metal of the evaporator is very cold and the air in the freezer is damp, frost starts to develop on the evaporator coils.  If left unchecked, this ice buildup can cause all kinds of damage.  So a defrost system was developed to periodically turn on and melt this ice.

Mechanical Defrost Timer

The defrost control is the brains of this show.  Every so often,

Adaptive Defrost Control

depending on the manufacturer's setting, this gizmo kicks into gear.  It shuts off the compressor and turns on the defrost heater that begins to melt the ice on the evaporator.  Newer refrigerators may have an adaptive defrost control or a motherboard that does the same thing.

Now the defrost heater starts heating up and melting that ice.  If you stand by your refrigerator when this cycle is in process, you can hear the ice melting and dripping into the drain trough where it goes to an evaporator pan under the refrigerator to evaporate on its own.

Defrost Heater

Now, once the defrost thermostat senses that temperatures have reached a certain limit, it turns the heaters off.  The defrost timer continues on its cycle until the set time has been reached.  Then it kicks the compressor back on and the cooling cycle begins again.

Defrost Thermostat

As you can see, there are a variety of things that may be in play if your refrigerator is not cooling like it's supposed to.  While I am a pretty handy person, I highly suggest you call a service tech to come take a look at your refrigerator.  This is something that I would not attempt to do.  Due to the government's mandate that appliances need to be water and energy efficient, manufacturer's have needed to find newer and better ways to accomplish this, hence the advent of more electronic boards and the education needed to decipher exactly why it is not doing what it's supposed to.  Call your favorite technician if you have problems.

Hopefully, this little tutorial has given you a better understanding on how your refrigerator works.

Have a great week!

Friday Morning Videos: GE Refrigerator Defrost System

Rich from Western Appliance Repair in Boise posted this short video explaining how a defrost heater in a GE works. Great for showing customers or trainees.



For more from education and entertainment from W.L. May Company click...HERE

Wednesday Worth Considering: Are You Ready For A Heat Wave?

Creative Commons license on image.

Summer brings to mind thoughts of vacations, picnics, beaches, and ball parks. If you are in the appliance repair business summer also brings some predictable service calls. For those of you in the trade, you want to be ready BEFORE the first heat wave hits your community. Once things get hot and start breaking, your preparation will pay off. When the temperature rises so tempers can rise and patience often goes down. If you are not ready to complete the job in one day, your potential customer may well try to find someone who can. This is definitely one of the times you want to make sure your truck is well stocked. I'd recommend paying particular attention to your refrigerator parts. Are you ready to install an icemaker when your customer requests it? Not on the next day, but on the same day. Do you have the defrost components and motors for the types of refrigerators that are common to your area? If you do sealed system work are you ready with fittings, freon and start devices? Or maybe a universal compressor or one of the more common boards? I'm sure that I have probably forgotten at least one common warm weather request, so I ask you: are there other items that you stock to prepare for heat-wave business? If so, please share them in the comments section. Have a great summer and don't forget to drink plenty of water!