Temperature not working
Before replacing the refrigerator's temperature controls, you should do some basic troubleshooting to make sure the problem stems from a defective control and not some other problem. The most obvious thing to check is that the refrigerator is plugged in and receiving power from the outlet. If it is running, but not cooling, it could be due to dirty condenser coils or a defective door seal. Once the coils are clean and the door seal has been checked, you can be pretty confident that the problem is the temperature controls.
There are usually two control knobs, one that controls the temperature of the freezer and one that controls the refrigerator. Although they appear to be independent controls, it is important to understand that the cold air comes solely from the freezer area into the refrigerator compartment. The freezer control determines how much cold air the condenser produces while the refrigerator control adjusts the flow of cold air from the freezer to the refrigerator compartment. If there is no cold air on either side, it is probably the freezer control that is at fault. The procedure to replace the control switch is the same for the refrigerator control and for the freezer control.
Even though we have gone through this troubleshooting, it is still a good idea to test the control mechanism before replacing it. You will need a multitester and possibly needle-nose pliers and a screwdriver for the testing. First, unplug the refrigerator so you don't get shocked. Then, remove the temperature control's dial and/or housing. The dial will just pull straight off, but the housing may have screws holding it in place. After removing the housing, just let it hang by its wires. There should be two wires attached to the control. Label them before disconnecting so it is easier to put back together. Remove the wires by pulling on the slip-on connectors, not the wires themselves. Needle-nose pliers may be needed to remove these connectors from the terminals, especially if the refrigerator is old.
Set the ohms setting on your multitester to X1 and attach one probe to each terminal. Turn the temperature control to off or to the warmest setting if there is no off position. The multitester should give you a reading of infinity if the control is on off and a reading of near infinity if there is no off position. Then turn the control to the coldest setting and retest. Now, the multitester should give you a reading of zero. If both of these tests are not passed, the control needs to be replaced.
You already have the dial part of the temperature control disassembled, but there is also a temperature probe attached to it. Remove all fasteners holding on the existing probe and take note of the path of the probe. Install the new temperature probe along the same path as the original. Do not bend at a sharp angle and try to avoid bending more than necessary so the probe does not get damaged. Attach the refrigerator's wires to the new temperature, replacing the connectors if corroded. Replace the switch and any necessary housing screws you removed earlier. Plug in the refrigerator and set the temperature control to the midpoint setting. The refrigerator should start cooling down within one to two hours.
The thermostat – that part of your fridge that controls the temperature – may be one of the smallest parts, but of course it is also one of the most important. The thermostat can not easily be repaired – generally speaking, if you have a faulty thermostat you will almost certainly need to have it replaced.
There are several warning signs that the temperature inside the fridge is not what it should be. An obvious sign that the temperature is too cold inside the fridge is when liquids – milk, soda or orange juice, for example – are partly frozen. Similarly, if your freezer or ice compartment is kept too cold, ice will form on the outside of packets of food that are stored in there. The bottom part of your fridge is the coldest part – you can always try putting produce and other sensitive food items on a higher shelf. Ice or frost forming on the inside walls of the fridge also indicates a problem. Food that spoils before it should is also a sign that your fridge may be too warm.
Before you spend the time and money replacing the thermostat, here are some tests you can perform to see if it is the thermostat that is faulty, or some other problem. If you feel the temperature in your fridge is not what it should be, firstly try the obvious: make sure the temperature control is set correctly. The ideal temperature for the fridge should be between 38 and 40 degrees Fahrenheit, and for the freezer temperature between 0 and 8 degrees Fahrenheit. The temperature setting may have arbitrary numbers on it, (for example 1 through 9, warmest to coldest) and simply moving this control to the next setting up or down may solve the problem. Depending on the age and make of your fridge, there may be separate temperature controls for both the fridge and freezer. Check the manufacturer’s manual that comes with your fridge to find the suggested setting for the temperature control – or call the manufacturer if you don’t have the manual. Most companies have a toll free help or troubleshooting number to call.
If you are technically minded, it is possible to easily unscrew the temperature dial, and then remove the actual temperature control box, taking care not to pull any wires away. You can then test the temperature control using a hand held device called a continuity tester probe. Set the control dial to its coldest setting, and then attach the probe. If it lights up, then this indicates a closed circuit with no obvious problem in the electrical system. Make sure your fridge is unplugged while you do this.
If your fridge temperature is too low and you cannot make it warmer by adjusting the thermostat, it may be one of several other parts that are causing the problem – there may be a leak in the refrigerant system, a defective air damper, or a situation known as cold air migration, which occurs in ‘side by side’ fridge/freezer models. Poor cooling can also be caused by frost building up on the evaporator coils – a vital part of the fridge that you cannot easily see without removing a panel on the inside of the freezer. A sure sign of this is if you see slight icing or frost build up on the inside walls, or floor of the fridge. If your fridge is self-defrosting, it may be a faulty defrosting mechanism that is causing the ice or frost build-up. One way to test this, although it is not particularly convenient, is to take everything out of the fridge, leave the door open and turn the thermostat off for at least 24 hours. Once the ice build up has disappeared, put the thermostat back on its normal setting – if the fridge then cools properly, there is probably a problem with some part of the defrosting system.
There are other ways to test that the thermostat is keeping your fridge as cool as it should. A good method of accurately checking the temp over a period of time is to leave a glass of water in the fridge for 24 hours; or a glass of cooking oil in the freezer. You can also use a thermometer – a meat thermometer is good for this. Also check the door seal and the door catch on your fridge – something as simple as the door not closing fully can cause a slight temperature increase inside the fridge. And leaving the refrigerator door open for long periods of time can also cause the inside temperature to warm up.
If you are lucky though, you may never need to repair your fridge – the average lifespan of a refrigerator is about 15 years, making them one of the most reliable and longest lasting of household appliances.
Good luck in solving the problem......
Aug 15, 2010 |