The refrigerator works around the clock to keep your food cold. If you think about how hard refrigerators work, it’s amazing that they don’t fail frequently. Refrigerator sometimes has some failures under complex working conditions for a long time. This article teaches you some basic working principles of refrigerators and simple refrigerator maintenance knowledge.
Refrigerator common fault detection Refrigerator radiator device
Each refrigerator has a radiator, 1. Some are installed on the back of the refrigerator in a mesh shape, 2. The closed refrigerator has a radiator. It is directly attached to the inner wall of the outer skin around the refrigerator. These two methods must be the latter arrangement if the cooling mesh cannot be seen behind. In the latter case, when we turn on the refrigerator, we will feel that the left and right sides of the refrigerator skin are hot. (Specially, there is a “heating” device connected in series at the bottom of the refrigerator, in order to evaporate the drainage from the chassis as soon as possible.
Why does the refrigerator door get hot; (except for the dew pipe device)
When the refrigerator is turned on, if you touch the surrounding of the door seal of the refrigerator with your hand, you will find that there are It is very hot. It turns out that this is because of the manufacturer’s interesting design. Because the inside of the refrigerator is very cold, and when the outside temperature is high, “sweat beads” will condense at the door, so the designers put the compressor outlet gas pipeline By the way, go around the door first, and use the heat of the pipeline to drive off the water droplets formed by condensation (this section of the pipeline is referred to as the “door sealing pipe”, also called the door sealing dew pipe).
The fault of the refrigerator is noisy. Detection process
1. External factors: the bottom corner is not flat, and the ground is not flat. Instruct the user to adjust the bottom corner of the refrigerator with the bottom corner wrench to make the refrigerator in a horizontal position; Move the adjoining items away or keep a certain distance from the wall of the refrigerator; the evaporating dish or condenser is loose, instruct the user to fasten the condenser or evaporating dish.
2. Normal sound: the user reports that the noise is too loud and does not It is allowed to actively measure noise to the user, and the user must be consulted first. If the user cannot accept it, the user can be measured. Before measuring the user, the national noise detection standard and detection conditions must be explained to the user. If the difference is within 3 decibels , you can consult the user that the measured value of the product and the marked value can have an error of 3 decibels, which is stipulated by the state, and the impact of the environment has not been taken into account. If the difference is greater than 3 decibels, and the noise is the normal sound of the refrigerator, just Consult the difference between the national measurement of refrigerator noise and the user’s use.
National standard of noise: the sound power level of the direct cooling refrigerator below 250L (including 250L) should not be greater than 45DB (A) Refrigerators above 250L should not be greater than 48DB (A)
3. Fan noise: check whether the fan is connected in series or the fan itself is noisy, replace the fan, check whether the fan blades touch each other and deform, and whether the fan is fixed Firmly, adjust or add rubber pads.
4. Compressor noise: Check whether the compressor is touching the surrounding pipelines, whether the compressor is loose, and whether the evaporating dish is loose. Adjust. Check the compressor for vibration damping If the glue is aging, replace it. Check whether the compressor itself is noisy and replace the compressor.
5. Solenoid valve noise: The solenoid valve has a loud commutation sound, first add shock-absorbing glue, if it does not work, The solenoid valve needs to be replaced. There is a messy humming sound, and the power supply board needs to be replaced.
6. Relay sound: the main control board relay sounds. When the refrigerator is working normally, the relay will make a suction sound. The main control board relay is ringing, check whether the power supply voltage is normal, and replace the main control board.
7. System noise: system wind blowing , This problem is mainly caused by the short evacuation time of the system and the air inside. Re-open the system to evacuate. The refrigerated evaporator emits a sound, open the back to check whether the capillary shock-absorbing glue is well fixed, and adjust the capillary. System grunts, open system maintenance.
The fault detection process of the refrigerator not cooling
1. The temperature zone is closed: Check whether each temperature zone is closed. At present, there are two ways to display the refrigerator when it is closed. One is to close a certain temperature zone and the temperature will not be displayed in the temperature zone. The other one turns off a certain temperature zone to display OF.
2. Sensor failure: If a certain temperature area is not cooled, such as a refrigerator room or a changing room, you can check whether the sensor parameters in this temperature area are normal.
3. The solenoid valve is not reversed: Check whether the solenoid valve is normal according to the solenoid valve detection method in the article “Fault Detection Process of Computer Refrigerator Freezing” on this website.
4. Capillary blockage: If there is no cooling in a certain temperature area, and the solenoid valve is normally reversed, it can be determined that it is a system problem, and the system needs to be further opened to determine.
5. System failure: Check whether the capillary is dirty, oil or ice. If the refrigerator does not cool down when it is refrigerating, it is usually blocked by ice. If there is no refrigerant in the open system, it means that the refrigerant is leaking, check the leak point and repair it.
6. Compressor failure: the whole machine does not cool, open the system, check whether there is enough refrigerant to be ejected, determine whether it is refrigerant leakage, no leakage, and check whether the compressor does not exhaust.
The fault detection process of the poor refrigeration effect of the refrigerator
1. The ambient temperature is too low: the ambient temperature is lower than 16 degrees, and the low temperature needs to be turned on Compensation switch, open but not heating, check the heating wire and magnetic temperature switch according to the detection method of mechanical refrigerator not starting. Below 3 degrees or even 0 degrees, please consult the user to increase the ambient temperature.
2. Food placement: Check whether the food is placed too much, especially the horizontal freezer should not exceed the food line.
3. Defrost problem: For manual defrosting refrigerators, check whether the refrigerator has not been defrosted for a long time, causing the frost layer to be too thick, resulting in the inability to exchange cold and heat, affecting the refrigeration of the refrigerator. For automatic defrosting refrigerators , Open the cover of the evaporator, and check whether the evaporator has a thick frost layer. If not, analyze it according to the process of the refrigerator not cooling. If there is a thick frost, check whether the resistance of the defrosting heating wire is normal, generally about 500 ohms. An open circuit indicates that the heating wire is damaged. Check the temperature limiter, if it is disconnected, it means the temperature limiter is damaged, check whether the defrost sensor is normal. The temperature limiter is fixed on the finned evaporator, and the outside is a transparent plastic cover. The temperature limiter is a non-recoverable part, and it must be replaced if it is damaged after disconnection.
Note: If the temperature limiter is found to be damaged, you cannot just replace the temperature limiter. You must check whether there are any problems with other related components to determine whether the main control board is faulty and has been heating. Check whether the resistance of the evaporating fan is normal. An open or short circuit indicates that the fan is damaged. For a refrigerator with a fan, damage to the fan will also cause frost in the refrigerator and affect the cooling effect. An open or short circuit indicates that the fan is damaged.
4. Door opening inspection: Consult the user whether the door is opened frequently, whether too much food is placed so that the door cannot be closed tightly, consult the user for correct use, and check whether the door seal has flash cracks, and the pressing area of the door seal (pressure whether the combined width should exceed 6mm) is enough.
5. Product placement: the product should not be exposed to direct sunlight, the ventilation should be good, and the heat dissipation back and side panels should be kept more than 10 cm away from the wall.
6. The thermostat or the main control board is faulty: adjust the temperature control gear to the appropriate gear. If the refrigerator is turned on for a short time, check whether the temperature of the back evaporator reaches the shutdown temperature. The shutdown temperature should be caused by a thermostat problem. When the shutdown temperature is reached, it may be a fault such as compressor overheating protection. If it is an artificial intelligence refrigerator, if the sensor is normal and the startup time is short, resulting in poor cooling, it can be determined that the main control board is a problem.
7. Sensor failure: If the cooling effect of a certain temperature zone is poor, you can refer to the computer refrigerator sensor detection method to check whether the sensor parameters of the temperature zone that control the temperature of the temperature zone are normal.
8. Poor compressor exhaust: Open the refrigerator system and check whether the compressor exhaust is normal. The simple method is to use your fingers to see if the compressor exhaust port can be blocked. It is judged that the compressor discharge is poor. If it is difficult to block, the second method needs to be used for further judgment. The first method is to connect a pressure gauge at the outlet of the condenser to check whether the exhaust pressure can be higher than 1.5Mpa and the gauge needle slowly retreats after the power is turned off. The compressor is not exhausted enough, if the indicator goes back quickly, it means the compressor is leaking.
9. Refrigerant leakage: If the compressor is normal, it can be judged that the refrigerant is leaking, check the leak point, and focus on checking the solenoid valve (which can be placed in warm water for more accurate leak detection) and the freezing lock ring to prevent Determined to be endoleak.
The fault detection process of the refrigerator running for a long time or not shutting down
1. The gear is too low: check whether the temperature control gear setting is too low. above, the artificial intelligence refrigerator should not be lower than 3 degrees.
2. The temperature is too low: check whether the refrigeration temperature is lower than 0 degrees or significantly lower than the set temperature, and analyze it according to the refrigeration freezing process.
3. Food placement: Check whether the food is placed too much, especially the horizontal freezer should not exceed the food line.
4. Defrosting problem: Check whether the refrigerator has not been defrosted for a long time, resulting in too thick frost layer.
5. Door opening inspection: Consult the user whether the door is opened frequently, consult the user for correct use, and check whether the door seal is flashed.
6. Product placement: The product should not be exposed to direct sunlight, the ventilation should be good, and the heat dissipation side should be kept more than 10 cm away from the wall.
7. Low temperature compensation check: For single-system refrigerators, check whether the low temperature compensation heating wire is still heated if the ambient temperature is higher than 16 degrees. If it is heated, check the magnetic sensitive temperature switch. If it is heated, the magnetic sensitive temperature switch is normal. , it can be determined that the main control board is faulty.
8. Poor cooling effect: Check according to the process of poor cooling effect.
The fault detection process of refrigerating and freezing of computer refrigerators
1. The set temperature is too low: check whether the temperature setting is too low. Generally, the gear should not be lower than 5 degrees in summer.
2. The temperature is too low: check whether the refrigerated temperature is lower than 0 degrees, and the normal temperature of the upper part of the fruit and vegetable box should be above 0 degrees (including the drainage outlet). If the temperature is low and zero, check the following aspects :
Sensor: Check the refrigerated space sensor or refrigerated evaporation sensor, and check the resistance value with the sensor parameter table to determine whether it is normal; Unplug it, detect the resistance value of the corresponding sensor, and use the thermometer to monitor the temperature value next to the corresponding sensor, read the temperature value and resistance value at the same time, and then check the corresponding sensor parameter table. If the resistance value matches the resistance value range corresponding to the temperature value, the sensor Normal, otherwise the sensor parameter drift fault.
Note: The sensor parameter drift will not display the sensor fault code. The code will only be displayed when the sensor is open or short-circuited. For refrigerated evaporation sensor to control the opening and closing of the refrigerator, check whether the temperature of the sensor temperature sensing point can reach the shutdown temperature. Generally, the shutdown temperature is -22~-26 degrees. If the temperature cannot reach, it will be repaired according to the poor performance of the refrigeration system. If the temperature is normal, the resistance value If it is not in the normal range, it can be determined that the sensor is faulty. It needs to be replaced (for the built-in push-to-open back process treatment and replacement), the shutdown point of the space sensor to control the startup and shutdown is generally the set temperature value. easier to judge. If the sensor resistance and the measured temperature correspond to normal, check whether the main control board and the solenoid valve part are normal.
3. Main control board: Check whether the solenoid valve can be reversed normally, and turn off the multimeter for refrigeration to check whether there is a pulse signal. If there is no signal, it can be judged that it is the main control board problem.
4. Solenoid valve: If it is not cooling in a certain temperature area, check whether the solenoid valve coil is normal, the normal resistance value of the coil is 1 to 2 thousand ohms, close the refrigeration or changing greenhouse, and check whether the solenoid valve is not Action, measure the pulse signal of the solenoid valve, use the multimeter digital AC gear 200V, the black test lead is connected to the power N line (blue) The red test lead is connected to V1 or V2, there is a commutation signal of about 70~100V, if the refrigeration solenoid valve is closed, a positive Pulse, open the refrigerating solenoid valve to generate a negative pulse, and the -7 degree pulse is positive and negative, but the solenoid valve does not operate, indicating that the solenoid valve is faulty, there is no signal, check whether the connector at the bottom of the box is connected properly, normal means the main control board is faulty .
Note: The difference between the solenoid valve connecting pipes: white: refrigerated, yellow: greenhouse, red: frozen.
5. If the inspection components are normal, please pay attention to check whether the wiring of each part is normal, focusing on the connectors on the engine room floor, the internal wiring of the box, and the wiring of the door.
6. If the temperature is normal, analyze it according to the detection idea of mechanical refrigerator.
Refrigerator Troubleshooting Removing the Refrigerator
The controls of a refrigerator are usually located on its top or the top half. The motor, compressor, condenser coil and condenser fan are located at the bottom.
To gain access to components in the top half of the unit, remove the set screws, or pry open the clips that hold the plastic (or metal) panels to the parts. These fasteners may be hidden by trim or molding, in which case use a hard-edged putty knife to pry the trim or molding off. Protruding control elements can also be used to secure individual panel components. In most refrigerators, the shelves can be removed to gain access to certain panels.
To access the lower half of the refrigerator, remove the service panel that is secured with set screws to the back of the refrigerator, below the condenser tube. The portion of the refrigerator below the door may also have a front access panel. The panel may be held in place with set screws, or it may be caught between two brackets on the side, which can be removed by sliding it up. On some models, you can lay it down and inspect and service parts from the bottom. In this case, the refrigerator must be defrosted, unplugged, and emptied before servicing.
The condenser coil, evaporator coil and compressor of most refrigerators are hermetically sealed. If there is any internal failure of these parts, please call for professional service. Other parts can generally be removed by unscrewing screws or prying loose from the mounting bracket.
Repairing Refrigerator Door Gaskets
When refrigerator gaskets (usually the rubber seal around the door) harden or crack, their seal will be weakened, greatly reducing the efficiency of the refrigerator. To test for leaks in the gasket on the door, place a one-dollar bill between the gasket and the door frame and close the door. Then pull the note out, if you encounter resistance, the gasket is probably intact; if you can pull the note without any effort, or if the note slips off by itself, there is a problem with the gasket and you should to replace. When testing gaskets, test at several locations around the door. Before replacing the gasket, check the door hinges for leaks.
Here’s how to replace the gasket:
Step 1: Purchase a gasket specific to your refrigerator model. So-called “universal” gaskets may work well after retrofitting, but tailoring them to the door’s construction can be a difficult job. If you’re unsure of your refrigerator model, cut off a small piece of the gasket and take this sample to your appliance dealer to find a matching product. If the gasket must be ordered, you can use rubber adhesive to glue the sample back into the notch as a temporary remedy until the new gasket arrives.
Step 2: Let the new gasket sit in the refrigerator room for 24 hours to have the proper temperature and humidity, or soak the gasket in hot water to make it pliable sex.
Step 3: Begin removing the old gasket. The gasket on the door is secured with screws, clips, or adhesive, and it may have a locating fillet to help it shape, and the fillet can also be used as a marker or indicator when it’s fixed. In some models of refrigerators, the gasket can be attached to the edge of the door panel, which is held in place with steel spring clips, bolts, or screws. To remove the gasket, first remove the fasteners that hold it in place, then remove any locating moldings, or remove the fasteners that hold the door panel in place.
Step 4: Remove the fasteners on only one side of the door at a time. Do not remove the entire door panel. If the gasket is held in place with spring clips, be careful not to use too much force when prying the clips, as the clips may pop out of their mounting locations under pressure. If the gasket was held in place with adhesive, use a putty knife to pry it off.
Step 5: After the old gasket has been removed, wipe the installation area thoroughly with a mild household cleaner and water solution. To remove stubborn buildup, scrub with a fine wire brush dipped in mineral spirits, then rinse with detergent or water.
Step 6: Begin replacing the gasket located at the top of the door. Go down the sides and replace the entire gasket. Put the gasket in place, level it out evenly, and loosen the sections at the corners. If specifically requested by the manufacturer, use gasket adhesive to secure it. Make sure to lay the gasket flat with no rolled up edges or raised parts.
Step 7: Replace fasteners, locating moldings, or panels used to hold old gaskets. After the gasket is in place, tighten or loosen the mounting bolts as needed to adjust how well the gasket fits the door frame. If the gasket is glued in place, your job is almost done, just wait for the gasket to stick to the door frame.
In the same way, use a one-dollar note to test the seal on the freezer as previously mentioned. If you find a problem with the gasket, replace it with a gasket designed for that freezer. Do not replace the gasket by removing the freezer door. The door of the freezer is often spring-loaded, which can be cumbersome to replace after the door is removed, and some models require the wires to be removed.
Servicing the Refrigerator Door Switch
There is a small push button switch on the door frame of the refrigerator. This part is used to control the lights in the refrigerator. If this switch fails, the light in the refrigerator may stay on all the time, so that the heat from the bulb can cause trouble cooling the refrigerator.
Step 1: Please check the light bulb to see if it is burned out. If not, press the button on the door switch.
Step 2: If the light is still on, clean the switch with a rag. Then remove the switch from the door frame. Remove the set screws hidden under the plastic trim and use a screwdriver to pry the switch out of the door frame, or pry the trim of the door frame to expose the switch. Then test the switch with a multimeter set to RX1.
Step 3: Clip the two probes of the multimeter to the two terminals and press the button. The meter should read zero. If the pointer on the dial points to a position greater than zero, there is a problem with the switch and it needs to be replaced with a new switch of the same type.
Step 4: Connect the new switch in the same way as the old one.
Service limit switch
Only frost-free refrigerators and frost-free freezers are equipped with temperature limit switches. Its function is to prevent the defrosted heating element from exceeding a predetermined temperature. If there is a lot of frost in the freezer compartment of the refrigerator, there may be a problem with the temperature limit switch. However, other components such as the evaporator fan, defrost timer and defrost heater can cause the same problem. Please follow the detailed instructions below to check for any malfunction of these components. If these components are operating normally, the problem is likely to be with the temperature limit switch. Do not try to repair the temperature limit switch yourself, but call a professional repairer to replace it.
Servicing the Thermostat
Thermostats are usually installed inside the refrigerator. The temperature of the refrigerator/freezer can be adjusted by turning its visible control knob. Depending on the situation, the effectiveness of this controller can be checked in a number of ways. Details are as follows:
Step 1: If the compressor has been running, turn the control knob to the OFF position. If the compressor is still running, unplug the refrigerator, then remove the control knob and remove the screws holding the thermostat in place. Unplug the thermostat and remove the red or blue wire from the terminal. Plug in the refrigerator. If the compressor doesn’t run, the thermostat is faulty. Please replace it with a new thermostat.
Step 2: If the compressor runs after removing the wires from the compressor terminals, there may be a short somewhere in the refrigerator wiring. In this case, don’t try to fix it yourself, but call a professional repairer for help.
Step 3: If the refrigerator or freezer is running but not cold inside, unplug the power and use a screwdriver to remove the thermostat. Disconnect the two wires from the thermostat. Wrap the ends of the wires together with electrical tape and plug them in. If the refrigerator starts and operates normally, the thermostat is faulty and should be replaced with a new thermostat of the same type. Connect this new thermostat in the same way as the old one.
Step 4: If the freezer compartment of the refrigerator is working properly, but the refrigerator compartment is not cold, turn the dials that control them to the middle position. Remove these knobs (they are usually held in place by friction) and unscrew the housing that houses the temperature controller. At this point you will see the air tube near the controller. Replace the knob on the freezer thermostat and turn it to the OFF position. Open the refrigerator door and take a close look at the air ducts. If the opening of this pipe does not widen within ten minutes, the controller is faulty and should be replaced with a new controller of the same type. Connect this new controller in the same way as the old one.
Servicing the Condenser Fan
The condenser fan is located under the refrigerator. If the fan fails, the refrigerator or freezer will not cool properly, or will run continuously, or not at all.
Please use a multimeter set to RX1 to check the fan. Disconnect the wires connected to the fan motor and clip the two probes of the multimeter to the two terminals of the motor. If the meter reads between 50 and 200 ohms, the motor is working properly; if it reads above 200 ohms, the motor is faulty and should be replaced.
When you service the fan motor, make sure the fan blades are clean and unobstructed. If the blades are bent, use pliers to straighten them carefully.
Cleaning the Drain Holes
Drain holes are located along the bottom of the refrigerator and freezer compartments. These holes can become clogged with debris or ice, causing poor drainage when the refrigerator defrosts. Use a small length of wire that fits into the hole for cleaning. Don’t use a toothpick, as the wood may snap in the hole, blocking it. Some refrigerators have drain holes located near the defrost heater on the evaporator coil, and cleaning this type of refrigerator requires extensive disassembly. If your refrigerator or freezer happens to be this type, it’s best to call a professional repairer to clean it.
The drain in some freezers is located below it, in the shape of a shoehorn. This drain can usually be unscrewed and the drain area cleaned.
Servicing the Drain Pipe and Drain Pan
The fan for the condenser is located under the bottom of the refrigerator. During defrosting, water can drain into the drain pan through a thin tube and evaporate naturally. Some refrigerator drains are made of rubber instead of metal. This type of hose can crack and cause leaks. Check the hose and if damaged, replace it with a new hose of the same type. If you notice water on the floor, the drain pan on the stand may be tilted, or the drain pan may be cracked or rusted. To eliminate this phenomenon, recalibrate the position of the drain pan, or replace it with a new one.
Servicing the Motor/Compressor
The compressor and motor of a refrigerator or freezer are housed in a sealed unit. If you track down and find that the problem is with one of these two components, do not repair it yourself, but call a professional repairer for help.
As you have already learned, some common refrigerator problems (like a malfunctioning gasket) are easy to fix at home, while some (like a malfunctioning motor or compressor) are beyond the capabilities of the average person scope. Now you know how to perform minor repairs and when to seek help.
There is also the price of refrigerator maintenance that everyone is more concerned about:
Make it clear that the door-to-door fee is 50-100 yuan.
It costs about 500 yuan to replace an ordinary hydraulic press, specifically about 200 yuan for the compressor, 100 yuan for the refrigerant (the price should have increased), about 10 yuan for copper pipe welding, and the rest is the labor cost.
It is suggested that ordinary refrigerators under 3,000 yuan have been used for more than 5 years. If you want to replace the compressor, you should buy a new one.
A repaired item is generally difficult to use for several years.
