Chapter 25 Installation and Troubleshooting of Domestic Refrigerators and Freezers 647 Copyright Goodheart-Willcox Co., Inc. 8 and eliminate the possible causes using a systematic, logical approach. The following sections describe some common problems found in domestic refrigerators and their possible causes. 25.2.3 Ice on the Evaporator A large buildup of ice on an evaporator acts as insulation, preventing heat inside the cabinet from being transferred to the refrigerant in the evaporator. When this occurs, the evaporator may not be able to cool the inside of the refrigerator. Ice buildup on the evaporator is usually caused by a leaky door seal (gas- ket). In a frost-free or automatic defrost refrigerator, ice buildup indicates that the defrost feature is not operat- ing properly. Faulty Gasket If the seal on a refrigerator door is not complete, external air will enter the conditioned space. This external air will add moisture to the system and cause abnormal frosting on the evaporator. The frosting could also be apparent on the walls of the compartment. If a gasket forms a poor seal in just one location, a heat gun can be used to apply moderate heat to that spot on the gasket. When the bad area of the gasket is suffi- ciently heated, it becomes pliable and can be reformed. Sometimes a small amount of silicone grease can be applied to the gasket to assist in creating an airtight seal. The grease allows the gasket to flex more easily and prevents binding as the door closes. Old or brittle gaskets allow heat to enter a refrig- erator and cool air to leak out. Signs of gaskets in need of replacement include increased system running time and condensation or mold on the gasket. To check for a faulty gasket, a slip of paper is placed between the door and cabinet, and then the door is closed. The slip of paper should be held tightly by the closed door. If the paper can be pulled out easily, the gasket does not form a tight enough seal. In some cases, the hardware (latch and hinges) can be adjusted to obtain a better seal. In other cases, the gasket may have become inflex- ible or broken and must be replaced. Replacement gaskets are specific to the refrigera- tor make and model. However, universal repair kits are available. The kit includes a roll of magnetic strip and four lengths of gasket material with preformed corners. The gasket material can be easily cut to the size needed, Figure 25-7. While removing an old door gasket, place the replacement gasket in warm water for a few minutes to make it pliable. Gaskets are often held in place by a metal strip (retainer) attached to the door. In these cases, lift the inside edge of the old gasket and slightly Troubleshooting Chart—Domestic Ice Makers Trouble Common Cause Remedy Cube produced by ice maker is too small. 1. Ice mold not correctly mounted. 2. Insufficient water delivery. 3. Faulty water valve switch. 1. Check that mold is in a level position. 2. Check supply water pressure and strainer for restrictions. 3. Check electrical contacts and operation. Automatic ice maker will not start cycle. 1. No power to ice maker. 2. Ice level indicator signal arm stuck in up position. 3. Ice maker motor shorted or burned out. 1. Check voltage to ice maker. 2. Check for obstruction blocking signal arm movement. 3. Check voltage to motor and motor operation. Automatic ice maker does not fill with water. 1. Insufficient flow or no flow of water to unit. 2. Ice level indicator signal arm stuck in up position. 3. Ice maker motor shorted or burned out. 1. Check main water supply flow. Clean all strainers. 2. Check for obstruction blocking signal arm movement. 3. Check voltage to motor and motor operation. Automatic ice maker does not complete cycle. 1. Faulty ice level indicator. 2. Cube heater or thermostat faulty. 1. Check for obstructions blocking signal arm movement. Test continuity of ice level indicator switch. 2. Check resistance of heater. Jump out thermostat. Goodheart-Willcox Publisher Figure 25-6. Common problems of domestic ice makers.