First, I'm not a Frigidaire tech.
* Check your warranty. Call for service.
* Contact (note Live Chat link); https://www.frigidaire.com/Owner-Center/Contact-Us/
*** following is for information only ***
* Checking basic problems; https://www.youtube.com/watch?v=SXJrVGP_Ixs
* The humidifier will only run if the "Humidity" (water or moisture in the air) is higher than the current setting on the humidifier. If it's set to maximum dry setting then expect it to run almost 100% of the time. If it is set to a "wet" setting then expect it run only for short periods.
* Colder room temperatures will reduce the frequency of cycles as cold air will hold less moisture than warm air.
* You may note that running a AC unit in the same room as the dehumidifier will give you mixed results as both units will "fight" or work against each other. Humidifier will heat the air as it exits while the AC will cool the air. Best to not run the AC while the dehumidifier is in operation.
* Note that AC do "dehumidify" the air as it passes through. But not as effective as a dedicated dehumidifier.
* Be sure to check the tub and filter (make sure they are seated properly.)
* Contact Frigidaire or your local Appliance store for service.