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HomeRepair HelpMammoth Central A/C RepairMammoth Central air conditioner coil icing up Repair
Mammoth Central air conditioner coil icing up
When a Mammoth central air conditioner coil is icing up, the evaporator coil may be frozen because too little air is moving across it or because refrigerant flow is not being regulated correctly. First, check whether the humidifier damper is open. It should be closed or set to summer mode, since an open damper can bypass the evaporator coil and restrict cooling airflow. Next, inspect the Mammoth air handler or furnace blower motor. A seized motor or blower wheel that does not turn freely can stop circulation and cause an evaporator coil frozen condition. A clogged blower wheel and housing can also reduce airflow, so clean it carefully with compressed air or a soft brush. If the blower motor will not run, a failed run capacitor or capacitor may be responsible. Finally, a defective thermal expansion valve, or TXV, can mismanage refrigerant entering the evaporator coil. Turn off power before inspecting electrical parts, and do not work inside a 240V circuit unless qualified. TXV, refrigerant, and other sealed-system repairs require an EPA 608-certified HVAC technician. Enter your Mammoth model number to find the exact blower motor, blower wheel, capacitor, or TXV replacement part for your unit.
01 - Humidifier Damper is Open
An open humidifier damper will let air bypass the evaporator coil. This loss of air flow can cause the evaporator coil to freeze up. If you have a humidifier on your furnace or air handler, confirm the humidifer damper is in the "summer mode" or closed position.
Highly Likely
02 - Mammoth Central Air Conditioner Blower Motor
Since the furnace or air handler blower motor is the component that circulates the air through unit to cool it, a defective blower motor could result in the evaporator coil icing up. You can use a multimeter to test the blower motor for electrical continuity, a continuous electrical path present in the motor, as well as determine if power is reaching the motor. You can also try turning the blower wheel by hand. If the wheel does not turn freely, it's likely the motor bearings have seized and the blower motor will need to be replaced.
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Highly Likely
03 - Mammoth Central Air Conditioner Blower Wheel and Housing
Over time the blower wheel and housing can become clogged with dust and debris. This will restrict the air flow which could result in the evaporator coil icing up. You can try cleaning the blower wheel with compressed air or with a soft bristle brush. Use caution when trying to clean the blower wheel as the fins are sharp and can be easily damaged. If the blower is damaged it will need to be replaced.
Common
04 - Mammoth Central Air Conditioner Run Capacitor
If the run capacitor is defective, the blower fan motor may fail to run which could result in the evaporator coil icing up. To determine if the run capacitor has failed, test the capacitor with a multimeter. If the capacitor is unable to hold and release a charge or is bulging or leaking, replace it.
Common
05 - Mammoth Central Air Conditioner Capacitor
If the capacitor is defective, the blower fan motor may fail to run which could result in the evaporator coil icing up. To determine if the capacitor has failed, test the capacitor with a multimeter. If the capacitor is unable to hold and release a charge or is bulging or leaking, replace it.
Common
06 - Mammoth Central Air Conditioner Thermal Expansion Valve
A thermal expansion valve, commonly referred to as a TXV, regulates the amount of refrigerant in the evaporator coil to help maintain an optimal working temperature.
Common
Frequently Asked Questions
Why is my Mammoth central air conditioner coil icing up?
What should I check if my central air conditioner is not blowing enough air?
How do I troubleshoot a Mammoth AC blower motor that is not running?
Can a bad TXV cause an evaporator coil to freeze in a central air conditioner?
How do I find the correct Mammoth central air conditioner replacement part?
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