The glycol chiller should turn off at 29 degrees and turn back on about 32. Be certain that the condenser is clean with no dust accumulation. Also, be certain that the thermostat bulb is submersed in the bath and not against the coils. Hopefully the bath is not freezing against these coils.
Use a
refractometer to test the glycol freeze point. You should have around a zero to five plus degree bath freeze point on most units less thin plate heat exchangers (no coils).
Scott Zuhse, Instructor
Micro Matic Dispense Institute