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Friedrich Air Conditioner CHECK FILTER Error Code
Filter cleaning reminder on Friedrich air conditioners.
FriedrichAll Friedrich air conditioner codes
A reminder, and nothing is broken. Friedrich units count fan run time and light Check Filter when the filter is due for a wash. Kuhl units show it after 500 hours of fan run time, and the UE10D33C after about 250 hours.
Compatible models
Friedrich Kuhl window and wall units (SS, SM, SL, ES, EM, EL, YS, YM and YL series per its Kuhl service manual), plus the UE10D33C through-the-wall unit.
Also shown as
How you clear it depends on the model. On the UE10D33C, the reset only works from the unit's own control panel, not the remote.
Difficulty
Most people can clear this one at home with simple checks.
Not sure you are reading the code right? See how to read Friedrich air conditioner codes.
How to fix Friedrich CHECK FILTER
Wash the filter
Unplug the unit. Slide out the filter, wash it in warm, soapy water, rinse it, and let it dry completely before putting it back.
Clear the reminder
On the UE10D33C, press the two temperature arrow buttons together on the unit's panel. Kuhl owners can reset it through the Filter Reset special function; your manual shows the buttons.
Check it monthly in summer
Friedrich's owner's manual for its KCS, KCM, KCL, KES, KEM and KHS models says to clean the filter at least once a month, and more often when the room calls for it.
When to call a technician
Call for service only if the reminder won't clear after cleaning and resetting it, or the unit stops cooling well with a clean filter.
Parts linked to CHECK FILTER
These are the parts most often behind this code. Tap one to see what it does and the signs it is failing.
- air filter
Order parts by your full model number so they fit.
Frequently asked questions
Which Friedrich models show the CHECK FILTER code?
Friedrich Kuhl window and wall units (SS, SM, SL, ES, EM, EL, YS, YM and YL series per its Kuhl service manual), plus the UE10D33C through-the-wall unit.
Can I fix Friedrich CHECK FILTER myself?
Usually, yes. Most CHECK FILTER problems clear with simple checks you can do at home. Start with the first step above: wash the filter.
Other Friedrich air conditioner codes
- E1Short cycling or a sensor fault, depending on model
- E2Stuck button or a sensor fault, depending on model
- E3 / E4Frost probe open or shorted
- E5 / E6Room temperature probe open or shorted
Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.