Whirlpool Freezer Fan Noise in Safety Harbor: Ice Buildup From a Defrost Thermistor Reading Warm
- Symptom
- The fan in a Whirlpool French door fridge was making noise.
- Cause
- Ice had built up around the fan. The defrost thermistor read like a warm coil even with the coil iced over, so the control ended every defrost cycle early.
- Fix
- We replaced the defrost thermistor (Whirlpool part WPW10383615) and cleared the ice off the coil.
A client in the Amber Glades community of Safety Harbor called about a noisy fan in their Whirlpool French door refrigerator (model WRF560SMYW04, made in 2015). The fan was making noise, all right, and we found out why.
Ice around the fan
The noise was coming from the freezer. With the drawer out, the back panel was covered in frost, and behind it the coil was packed with ice that had grown up around the fan.
A fridge shouldn’t hold that much ice. Every so often it runs a heater to melt the frost off the coil, and a sensor tells it when the coil has warmed up enough to stop. Here the defrost system did run, just never all the way through.
Checking the sensor
The sensor is a thermistor, and its resistance changes with temperature. We checked it with the meter and it read about 8 kΩ. That’s what you’d see on a coil that’s already warm, and this one was buried in ice. So the control thought defrost was finished and shut the heater off early, every time. A little frost stayed behind after each cycle, and we think it piled up over the years until it started to block the fan.
New thermistor, clean coil
We replaced the thermistor with a Whirlpool factory part, WPW10383615. The old one is on the left.
Then we cleared all the ice off the coil.
With a good sensor the fridge can finish defrost the way it’s designed to, and the ice shouldn’t come back. We found a similar problem on a Whirlpool in Palm Harbor. If a fan in your fridge gets loud, frost behind the back panel is a common reason, and our refrigerator repair visits cover checking for it.
FAQ
Why would ice build up around my freezer fan?
If defrost ends early, a little frost is left on the coil every time. It piles up slowly, sometimes for years, until it reaches the fan and starts to block it. That's when you hear the noise.
Can the defrost system work and still leave ice behind?
Yes. The heater can come on and melt some of the ice, but if the thermistor reads warm while the coil is still frozen, the control shuts the heater off early. On this Whirlpool the thermistor read like a warm coil, so we replaced it.