Dehumidifier Freezing up
Once it freezes up, I think what you need to do is just let it thaw out. Otherwise, it's constantly building up ice. I find it strange that mine froze up. It's supposed to be rated for cold basements down to 42F. I mean, it's been working fine for 3.5 years now, so one freeze is not a big deal. It's a Fedders brand with a Maytag sticker over it.
The fan ran fine, so it should pull enough air. Big reason for potential air restricition is a dirty filter and/or dirty fins. If it freezes up, that also will block air flow.