Does the chiller system reach the 27 F setpoint and compressor shut off, or does the compressor keep running and the unit not reach setpoint? How quickly does the fermenter pull down to 36 F? The closer you get to your glycol temperature, the harder it is going to be cool. 32 F seems pretty low for a desired pull down temperature.
A safe glycol percentage is 33% glycol to 67% Water, giving you a freeze point around 0 to +5 F, you want the freeze point to be 20 to 25 F below your chiller system setpoint. This thread on this site has a few different methods for testing the concentration.
Frost on the pipes is normal, a big accumulation of ice is not good. One of the biggest issues that we receive technical support calls for are the result of lack of glycol in the system- I think you are correct to say this is the best place to start.
Once you have confirmed there is a correct percentage of glycol, I would look at a possible flow issue through your fermenter jacket. You could have air trapped in the jacket, improper pump rotation (check Chiller Manual or call mfg to confirm this), or a piping issue that could be causing this.
Hope this helps, good luck with your new job.
Pro Refrigeration Inc.