Cement Kiln in 5.5.4 doesn't work, until renamed.
I just spent the last 3 days trying to pump out my first cement blocks, even though I had the kiln correctly setup and fueled, according to the status screen. After numerous attempts to remake the roof, chimney, and location of the kiln, I finally, randomly, renamed the kiln to SlowMoney's HempCrete Kiln, and poof the @#$@ thing works.
Additionally, I noticed that when I had the Blast Furnace setup in the same room, the cement kiln would sometimes show the status of the Blast Furnace instead.
I assume these things are somehow related, since changing a name, a variable name from your side of things, seems to cure the issue.