Fedders Air conditioner has poor temperature control
If your Fedders air conditioner has poor temperature control, cycles off too soon, runs too long, or leaves the room warmer or more humid than it should, start with the parts that most often affect sensing and airflow. The most likely cause is a faulty temperature control thermostat, which may stop sending power to the fan and compressor before the room reaches the set temperature. A clogged air filter is also highly likely, since restricted airflow can reduce cooling capacity and cause the evaporator coil to frost over. Dirty or damaged filters, clogged or restricted coils, and buildup on the evaporator coil can make an AC not maintaining temperature problem worse. Less common causes include a bad thermistor connected to the control board or dirty condenser coils that cannot release heat properly, forcing the compressor to run longer. RepairClinic.com can help you confirm the cause, then you can enter your Fedders model number to find the exact temperature control thermostat, air filter, thermistor, or other replacement part made for your specific air conditioner.
01 - Fedders Air Conditioner Temperature Control Thermostat
The temperature control thermostat is a sensor which monitors the temperature of the air and activates a switch to provide power to the fan and compressor when the air temperature drops below a set point. If the thermostat isn’t working properly, the air conditioner may not stay running long enough to remove the moisture in the air and cool properly. To determine if the temperature control thermostat is defective, use a multimeter to test it for continuity. If the thermostat does not have continuity, or is shutting off too soon, replace it. (Note: Some thermostats may also control a heater and, as a result, will have three... terminals. Refer to your air conditioner’s wiring diagram for more information.)
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If the air filter is clogged, air cannot flow properly through the air conditioner. This greatly reduces the cooling capacity of the air conditioner. In addition, if the air filter is clogged, the evaporator coils will frost over. Most air filters used in stand-alone air conditioners can be cleaned with soap and water. Only filters that are extremely clogged with debris or damaged will need to be replaced.
If the air filter becomes clogged with dirt, it restricts air flow over the evaporator coils. If the air flow is reduced, the evaporator coils get too cold, which then causes the humidity in the room to condense on the coils and freeze. As frost accumulates on the coils, the frost restricts the air flow even more. Eventually, the entire evaporator coil assembly will frost over, causing the air flow to be completely restricted. Most air filters used in stand-alone air conditioners can be cleaned with soap and water. Only filters that are extremely clogged with debris or damaged will need to be replaced.
Common
04 - Clogged or Restricted Coils
Both the indoor and outdoor coils need to be clean for the air conditioner to work efficiently. A clogged or restricted coil will reduce air flow causing the unit to run inefficiently and longer.
Common
05 - Fedders Air Conditioner Thermistor
The thermistor is a sensor connected to the control board that detects the temperature of the air. The resistance value of the thermistor changes in conjunction with the air temperature. If the air temperature rises, the resistance value will decrease. To determine if the thermistor is at fault, use a multimeter to test it for continuity. If the thermistor does not have continuity, or if the resistance of the thermistor does not change with a change in temperature, replace the thermistor. (To find specific temperature and resistance values, try checking your user’s manual.)
The condenser coils dissipate the heat as the refrigerant passes through the coils. If the condenser coils are dirty, they won’t be able to dissipate the heat as effectively. As debris builds up on the coils, the air conditioner will become less efficient, causing the air conditioner to work harder to cool down. If the coils are significantly dirty, the air conditioner will not be able to remove the moisture from the air and maintain the proper temperature, resulting in the compressor running continuously in an attempt to cool the room. Check the condenser coils to determine if they are dirty. Refer to owner's manual for cleaning instructions.
Less Common
Frequently Asked Questions
Why does my Fedders air conditioner have poor temperature control?
Why is my Fedders AC not cooling or removing humidity?
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Why does my Fedders air conditioner keep running but not maintain temperature?
How do I find the right Fedders air conditioner thermostat, thermistor, or air filter?