Evaporator Fan

Evaporator fans are located in the freezer compartment behind a metal or plastic bulkhead and pull air over the evaporator coil and circulate it throughout the unit. Almost all refrigerators have a damper assembly that controls the amount of air entering the fresh food compartment from the freezer. Normally this damper is manually adjusted, but on some models it is electronically controlled. Another complicated and unnecessary part for the factory authorized repair person to chuckle over when you pay a couple of hundred to replace it. The old knob and plastic damper solution worked as well and rarely had to be replaced.

Normal-Fridge-Sounds_245x400_2

 Evaporator Fan (2) pulls air over evaporator coil (1)

The evaporator fan is wired to run when the compressor is running. If the evaporator fan fails the compressor will run longer since there will be no air flow to the fresh food compartment where most cold control sensing bulbs are located. The temperature will go up in the fresh food compartment and the evaporator coil will ice up causing the freezer temperature to rise.

Sometimes a defrost problem will ice up the evaporator and jam the fan blades. Before assuming the evaporator fan is bad, disconnect power, remove cover from fan and evaporator coil, and ensure that blade is free to turn. With power off, disconnect the wires from fan motor and read windings with volt-ohm meter. A reading of infinity indicates an open motor winding and the motor should be replaced.

If the fan blades are impossible or difficult to turn suspect a seized bearing. An evaporator fan with bad bearings occasionally emit a high-pitched squealing noise that is impossible to ignore.  

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10 Comments

Filed under appliance, diagnose and repair, refrigerator repair

10 responses to “Evaporator Fan

  1. glenn

    hi fridgeman -

    i am not sure, but i believe i have a faulty evaporator fan motor. by faulty i ,ean it has grown very loud, and runs constantly, and is slowly driving me insane. the fridge is GE, a side by said, and the sound is coming from the behind a plastic bulkhead above the icemaker (which does not sork as well.) and advice. i like the blog btw way, nice clear writing.

    best, glenn

  2. Robbie

    Thank you for this information! Our GE refrigerator just went out the other day, but we thought it was strange that it was only the fresh food compartment that became room temperature and not the freezer side. The frige has also made strange high-pitched howling noises since almost day one, just like you described. So I went online to look up the problem and landed on your blog. Now that we know what the problem is my dad won’t have to blow a thousand bucks on a new frige. Thank you very much!

  3. roy

    I got infinity reading on my fan that it will not run when the refrigrator is on. But the motor does run when I connect it directly to the power source. Is the fan defective?

    • fridgeman

      The fan is good. Some evaporator fans are wired in series with the defrost termination thermostat to prevent the fan from running during the defrost cycle. The termination thermostat is clipped to the evaporator and must cool to less than its reset temp before the evap fan will run.

  4. Emma

    Hi,

    I’m wondering what could cause a evaporator fan to stop working? My fridge was only 3.5 years old, is it common to need to replace them so soon. Could it have been damaged from leaving it in storage for 2.5 months without running it? Or is it more likely to be damaged by transporting the fridge to our new home?

    I am curious, as I would like to know in future if a fridge is in storage, should it be left turned on? We stored ours and turned it on only briefly twice during that time, and then had to replace the evaporator fan!

  5. Pat Michel

    We have an OLD GE frost-free refrigerator in the basement. We usually only use the refrigerator compartment. The evaporator fan in the freezer began loudly vibrating when it ran. I tried tightening it down and adjusting it, but it didn’t work. Can we run the appliance without the evaporator fan, disconnecting it? If we decide to replace it, we’ll just buy a small 10 or 11 cu. size anyway.
    THanks.

  6. Schalk

    On the defrost cycle of a freezer , is it nessesary for the evaporator fans to run or not ??
    Thanks

    • fridgeman

      Most evaporator fans stop during the defrost cycle to keep the heat confined to the frosted evaporator coil rather than circulating heated air to the frozen food.

  7. Todd

    Am I correct in assuming that really old, antique fridges (before separate freezer compartments came along) didn’t use a fan to distribute cold air? Can’t find one on anything prior to about 1950.

    Thx.

    • fridgeman

      Correct. There was usually a small freezer box formed from the evaporator at the top of the refrigerator compartment. Circulation was by gravity…cold air is heavier and sinks to the bottom as warmer air rises. Fans appeared in the late 50s and became the norm in the 60s along with separate freezer and refrigerator sections.

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