FILTER MISSING ERROR (Filter Out)
Cause
A “FO” (FO) error code will display, and the machine will not start if the lint filter is left out of the machine. A magnet embedded in the lint filter activates the reed switch mounted internally in the plastic housing of the vent duct.
Solution
Check for lint filter installed and if not then properly install the filter.
Check lint filter reed switch for continuity.
DETAILS BELOW:
There is a magnetic switch mounted to the side of the lint filter housing behind the front panel of the dryer. The magnet is made into the lint filter and when properly installed closes the magnetic switch so that the Main PCB knows the filter has been installed.
With the Filter installed there should be continuity read across the switch and if checking ohms will give a very low value, normally around 0.3Ω as shown below…
With the Filter removed there will be no continuity across the switch and if checking ohms should give a higher resistance as shown below…
If checking voltage you would see 5Vdc with the filter removed and that voltage will drop to 0Vdc with the filter installed correctly…
The filters and magnets can look different per model. Below are some other examples that you might see but the principles of how the magnetic switch circuit works will still be the same…
