Abnormal Vs. Normal Noise; Evaporator Freezing - EdgeStar CWB8420DZ Service Manual

9.4.10 Abnormal Vs. Normal Noise

- Compressor Noise
The working of the electrical motor and the pump inside the compressor will cause
noise during its run time. The noise should be stable and not exceed 42 dB(A). If the
noise is excessive, the compressor is defective and should be replaced.
Aging rubber legs or incorrect leg mounting (Too loose or too tight) also generates an
abnormal noise. If so, please correct the leg mounting or replace the legs.
- Fan Noise
A working fan motor will cause noise during its run time. The noise should be stable
and not exceed 40 dB(A). If the noise is excessive, checking the following:
If the bearings of the fan motor are defective, replace the fan motor.
If the fan blade interferes with the wiring, fix the wiring.
- Refrigerant Flow Noise
If the end of the capillary tube was inserted too far into the inlet pipe of evaporator or
there are burrs at the end of the capillary tube.
The anti-vibration grommet mounted to the joint of t h e capillary and inlet
tubing of evaporator is lost.
The capillary tube is interfering with the other parts or refrigeration lines.
The compressor oil has flowed to the refrigeration tubing during transportation.
Perform a system flush and recharge.
- Normal Noise
All models incorporate rigid foam insulated cabinets to provide high thermal efficiency
and maximum sound reduction for its internal working components. In spite of this
technology, your model may make sounds that are unfamiliar. Normal operating
sounds may be more noticeable because of the unit's environment. Hard surfaces
such as cabinets, wood/vinyl/tiled floors and paneled walls have a
tendency to reflect normal appliance operating noises. Some common refrigeration
components, and a brief description of the normal operating sounds they make are listed
below:
Compressor: The compressor makes a hum or pulsing sound that may be heard
when it operates.
Evaporator/Capillary: Refrigerant flowing through an evaporator may sound like
boiling liquid.
Condenser/Evaporator Fan: Air moving through a fan can be heard.
Automatic Defrost/Drain Pan: Water may be heard dripping or running into the drain
pan when the unit is in the defrost cycle.
At the end of each cycle, you might hear a bubbly noise coming from the fluid
circulating in the pipes.
The interior walls contracting and expanding may also cause clicking or cracking
sounds.

9.4.11 Evaporator Freezing

The evaporator will freeze because of the following reasons:
The evaporator fan motor has failed. Check the door switch and if it has failed replace the
door switch. If the fan motor is defective, replace the fan motor.
Frequent power
The door is open for too long a time.
Faulty seal between the door gasket and cabinet front. Use a hairdryer to heat the portion
of the gasket that is not sealing correctly and then pull the gasket to make it contact the
cabinet front. If this does not work replace the door gasket.
outages.