.Like an air conditioner, a refrigerator operation a standard refrigeration cycle. A compressor force refrigerant through two connected sets of coils. In the low-pressure area of the evaporator coils inside the unit, the refrigerant becomes a gas and absorbs heat. In the high-pressure condenser coils outside, the gas becomes liquid and loses heat to the room air.
Frost buildup is a major obstacle to efficient refrigerator operation. Most models use either an automatic frost-free or a semiautomatic cycle-defrost system to melt the frost. On frost-free models, a timer turns on a defrost heater about twice a day to warm the evaporator coils—the place where frost collects. The coils are encased in the back or floor of the freezer along with a fan that circulates air over the coils and into the food compartments. A cycle-defrost system keeps only the refrigerator free of frost; the freezer must be defrosted manually. On both types of defrost systems, the melted frost drains into a pan under the unit and evaporates.
Repairs to the sealed refrigeration system—the compressor, condenser coils, and evaporator coils— are best left to a professional. But repairs to most other parts are relatively easy. A common problem is lint- and dust-clogged condenser coils; with airflow across the coils blocked, the unit may stop running or run continuously. Vacuuming the coils regularly will extend the refrigerator’s life and reduce running costs.
= = = ENVIRONMENTAL HINTS = = =
Ozone-destroying refrigerants:
If you have work done on the refrigeration system of your refrigerator or air conditioner, don’t be surprised if there’s an extra charge for capturing the old refrigerant. It’s illegal to release ozone-depleting chlorofluorocarbons (CFC’s or Freon) and hydro-chlorofluorocarbons (HCFC’s) into the atmosphere. If you are discarding an old appliance, you may also have to make some arrangement to have a licensed technician cap ture the refrigerant; call your local sanitation department. Restrictions on the manufacture of CFC’s began in 1995. Recycled CFC’s are being used to recharge existing units; most new refrigerators use less damaging substances.
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Note: Details of repair and disassembly may vary, depending an appliance model; If your refrigerator differs markedly from this one or the cycle defrost model see Appliance repair basics.
Evaporator fan; Airflow baffle; Door gasket; Condenser coils; Compressor; Front grille; Start relay and overload protector
Troubleshooting:
SYMPTOM: |
POSSIBLE CAUSE: |
SOLUTION: |
Won’t run; light off Won’t run; light on Cycles on and off often Runs all the time or cools poorly Gets too cold Doesn’t defrost Shell sweats Leaks inside or on floor Noisy Light out |
No power or faulty power cord Thermostat off Overheated compressor Obstructed or faulty condenser fan Faulty thermostat Faulty defrost timer Faulty start relay or overload protector Faulty compressor Dirty condenser coils Obstructed or faulty condenser fan Mis-positioned thermostat sensing tube Faulty start relay or overload protector Faulty compressor Thermostat too high or too low Frost buildup Dust-clogged condenser coils Obstructed condenser fan Frosted evaporator plate (cycle-defrost unit) Door not closing by itself Warped door or damaged door gasket Lights stay on when door is closed Faulty defrost timer Faulty condenser fan Faulty thermostat Faulty evaporator fan Loss of refrigerant Thermostat too low Faulty thermostat Faulty defrost heater or defrost limit switch Faulty defrost timer Exterior moisture switch off or faulty Faulty mullion heater Clogged drain tube Misaligned drain pan Leaky icemaker inlet valve Refrigerator not level Tubing hitting cabinet Obstructed or faulty condenser fan Evaporator fan faulty or hitting frost Loose or burned-out bulb Faulty door switch |
See General troubles/looting Turn thermostat on. Vacuum condenser coils Remove obstruction. Or test and replace Test and replace Test and replace Test and replace Test and have serviced Vacuum coils Remove obstruction. Or test and replace Reposition Test and replace Test and have serviced Put on colder or warmer setting. See Doesn’t defrost. Defrost cycle-defrost model Vacuum coils Remove obstruction. ‘ Wash with dishwasher detergent; rinse well Level refrigerator Check and realign door Or replace gasket Test and replace door switch Test and replace Test and replace Test and replace Test and replace Have appliance serviced. Put on warmer setting. Test and replace Test and replace Test and replace Turn switch on Or test and replace Have heater serviced. Clear tube Reposition pan Tighten plumbing connections. Or replace valve. Level Gently bend tubing away. Remove obstruction. Or test and replace Test and replace If frosted, see Doesn’t defrost. Tighten or replace. Test and replace |
[Degree of difficulty: Simple ---Average ---Complex---Volt-ohm meter required]
Gaining access:
To open front grille, grasp it near the ends and gently pull it straight out. On some models, swing the bottom out and up.
CAUTION: Always unplug the refrigerator (or turn off power to it at the service panel) before opening it for repairs.
To remove rear access panel, use a nut driver or screw driver to remove screws holding panel in place. Removing this panel allows you to reach the compressor and condenser fan and coils.
To access control panel, remove its front cover, usually held by a couple of screws and fitted into slots in the cabinet at the sides. Then unscrew the control panel from top of refrigerator compartment.
To reach evaporator and defrost heater, take out the screws in back of the freezer and carefully pull out back panel. On some models, these parts are under the floor of the freezer; to reach them, you take out the freezer’s bottom panel.
Door repairs:
A damaged gasket or a warped or sagging door makes the refrigerator run overtime (and encourages frost in a non-frost-free model). Besides the dollar bill test, you can check the door seal by putting a 150-watt outdoor floodlight in the compartment. Then darken the room and look for light seep age. Look at the door from different angles, moving the light cord away from the side you are checking.
When replacing a gasket, putting the new one in hot water makes it easier to handle. To keep the new gasket from bowing out at the corners, put a small bead of cord caulk (sold by refrigeration suppliers) under each corner.
A door often sags because the refrigerator is not level. Instead of adjustable casters, many models have threaded legs. To adjust them, tilt the refrigerator back, rest the front on a scrap 2 x 4, and screw the legs in or out.
The door light switch on some models is in the control panel, not in the door frame as shown below. To test it, open the control panel.
Replace gasket one section at a time. Lift old gasket edge and loosen (don’t remove) screws. Pull old gasket from under retainer strip, and slip new one into place. Retighten screws.
Check door seal in several places. Close door on dollar bill. Look for slight resistance as you pull it out. Or put light inside and look for seeping light in dark room.
To realign warped door, loosen gasket retaining screws slightly. Then grasp the door and twist it until it fits flush against frame when you close it. Retighten screws.
To tighten loose hinge, lift up door as you tighten hinge screws with a screwdriver or nut driver. Top freezer door hinge often has a plastic or metal cover that pops off with gentle prying.
To level refrigerator, place level on top. Remove grille; turn screw on each wheel (a clockwise turn raises unit). Tilting unit back slightly helps door shut better, but keep unit level if it has an icemaker.
To test door switch, unplug refrigerator, pry out switch, and take off leads. With VOM on RX1, clip probes to terminals. Look for infinity reading when you press in plunger, zero when you release it.
Condenser fan:
Poor cooling, a clacking noise, or short cycling may indicate a condenser fan problem. To reach the fan, unplug the refrigerator and remove the rear access panel. Before testing the fan motor, clean the condenser coils (see Use and care look for obstructed blades. If the blades still don’t spin freely, the motor has failed.
280c---
To test a fan motor, trace and disconnect leads. With VOM on RX1, probe terminals. Look for reading between 50 and 200 ohms; replace if much higher or infinity.
280d---
To replace fan motor, take out mounting bolts with socket wrench and lift out fan unit, being careful not to bend refrigerant tubing. A retainer clip usually holds blades on motor shaft.
Control panel:
The control panel houses the thermostat, its sensing tube, and the dial that controls a baffle that lets cold freezer air into the refrigerator. It may also contain the door light switch, the defrost timer, the defrost heater test terminals, and an exterior moisture control switch. This last switch (also called an energy saver switch because turning it off in dry weather saves energy) turns on a ‘mullion” heater that keeps the refrigerator shell from sweating on hot humid days.
To test thermostat, take off leads and turn dial to coldest setting. With VOM on RX1, probe terminals; look for zero reading. Unmount thermostat, set on warmest setting, and put in working freezer for 30 mm. Test again; look for infinity reading.
Check baffle that regulates airflow between freezer and refrigerator by moving dial that controls it. If damper doesn’t move, open control panel and check mechanical linkage between control and baffle.
To test exterior moisture control switch, take off leads. With VOM on RX1, clip probes to terminals. Look for zero reading when switch is on and infinity reading when switch is off.
Testing and replacing defrost timer:
This timer activates the heater that melts frost in the evaporator for 10 to 20 minutes every 10 to 12 hours. In the process, it turns the compressor off and on. If it fails, the compressor may not run. Or the heater may not go on, eventually causing a hidden ice buildup that blocks the cold-air flow and disables the evaporator fan. An access hole lets you test the timer. If the timer isn’t in the control panel, look behind the front grille or behind the rear access panel.
1. If compressor fails to run, turn timer until it clicks. If compressor goes on, timer is faulty. If unit isn’t defrosting automatically and turning timer stops compressor or fan, timer is faulty.
2. Before replacing timer, spray it with electrical contact cleaner through access hole and turn it a few times. Stop just before a click and wait to see if timer advances on its own.
3. To replace timer, unplug refrigerator and open control panel. Remove screws holding timer to panel and pull off leads. If wires aren’t in a plug, move them one at a time to new timer.
Compressor:
To reach the compressor, unplug the refrigerator and open the rear access panel. Take off the spring clip holding the box cover on the compressor. Then pull the overload protector and start relay off the compressor pins. On some models, the overload protector is like the one shown for an air conditioner and the relay like the one shown for a dehumidifier. If the unit has a capacitor instead of a start relay, be sure to discharge the capacitor first.
Box on compressor covers overload protector and start relay. These two parts fit together and plug onto compressor’s pin terminals.
Test overload protector with VOM on RX1. Probe the wire terminal and the terminal that fits on the compressor pin. Look for zero reading; replace if infinity or high ohms.
Test start relay with VOM on RX1. Remove a lead and probe terminals that fit on compressor pins. Look for reading of 20 to 100 ohms; replace if much higher or lower.
Probe all possible compressor pin pairings with VOM on RX1. Look for partial resistance on each. Test for ground on RX100: Probe bare housing and each terminal. All should read infinity.
Evaporator and defrost heater:
In a frost-free unit, the evaporator coils, their fan, and the defrost heater are located behind the freezer’s hack wall or under its floor. The fan, which circulates cold air between the coils and the two food compartments, is controlled by the door switch, the thermostat, or both. To check the fan, open both doors, wait for the compressor to go on, and hold in the door switch. If you can’t hear the fan running, test the fan.
The defrost heater, which melts frost on the coils, is cycled on by the defrost timer. If the frost melts before the end of the defrost cycle, the defrost limit switch turns the heater off. The heater may be a metal rod, a wire wrapped in foil, or a coil inside a glass tube. All are tested the same way. Test terminals for the heater are often located in the control panel or under a doorjamb; check the wiring diagram. Or test the heater leads inside the evaporator compartment.
The evaporator compartment: Defrost limit switch; Fan vents; Evaporator fan; Fan housing; Defrost heater; Evaporator coils
Testing the evaporator fan:
282b---
1 To remove the evaporator fan, unplug unit; open back panel (or floor) of freezer. Then unscrew housing holding fan, and take off leads going to fan motor.
2. With VOM on RX1, probe motor terminals (except green ground wire terminal). Look for moderate resistance (50 to 200 ohms). Replace fan if much lower or infinity.
Testing the defrost heater:
To test defrost heater, open control panel. With VOM on RX1, probe test terminals. Look for 15- to 100-ohm reading. If infinity, turn defrost timer; test again.
Testing defrost limit switch:
To test defrost limit switch, trace and disconnect leads. With VOM on RX1, probe leads. Look for infinity reading when switch is warm, zero after 20 mm. in working freezer.
= == USE AND CARE = = =
Check the temperature of both the refrigerator and freezer compartments periodically. In the refrigerator compartment, let a glass of water cool near the center of the compartment for 24 hours. Then put a refrigerator-freezer thermometer (sold at houseware stores) in the water for a few minutes. Look for a reading between 34° and 40°F. In the freezer, insert the thermometer between two food packages that have chilled for 24 hours. Look for a reading between 0° and 4°F. If necessary, adjust the temperature setting and repeat the test.
Vacuum the condenser coils under (or on the back of) the unit regularly—more frequently if you have a shedding pet. Unplug the refrigerator and push the crevice tool as far under the unit as you can. Try not to bend the con denser tubing or the coil fins.
For maximum efficiency, keep a freezer compartment full of frozen items but leave room for air to circulate between items in the refrigerator compartment.
Wash the compartments, drawers, and shelves twice a year with a solution of baking soda and water. Also clean the drain pan. Wipe the gasket every couple of months. Clean spills promptly.
Clear a clogged drain tube by using a baster to flush water through the tube. Then pour in a teaspoon of ammonia or bleach to prevent a recurrence of the probable culprit, algae spores.
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