The first step in troubleshooting why the Enclosure's Stir Fan or Heater will not turn on is to try and manually turn them on through the controller interface. You can do this by navigating to the Digital Outputs and manually setting them to "active" in DCTools. The Stir Fan and Heater output controllers are usually DO20 and DO21, but you should confirm the labeling before manually turning them on. The Enclosure's TEC is normally DO19.
If the item being tested turns on when manually set to active, the setting for the low threshold must be changed . In DCTools, navigate to analog inputs, and then expand the section that has the temperature inputs. On each temperature input, you can manually set the low threshold to what temperature you want, and also set the digital outputs to the corresponding outputs for the heater and stir-fan.
Specifically, in Analog inputs, expand the section listing temperatures, etc. to the right. You can choose what temperature input controls the TEC, heater, etc. But the default control input is the Lower Battery String Temp. input. To the right will be columns that say high threshold and low threshold. The high threshold should be the temperature that the TEC turns on, and the low threshold the temp the heater and stir fan come on at. To enable it, change the High Severity and Low Severity columns to Control for the temperatures that will control the trigger. Finally, map the high output to the TEC, usually DO19, and the low output to the heater and stir fan.
The default high threshold is 27 and low is 10. The hysteresis default is 3. That means if the TEC turns on at 27, it wont turn off until 24, and the heater will turn on at 10 and turn off at 13.
If when set manually to active, the heater/stir fan does not turn on, first check if the wiring is 120 or 240V. On 120V, the heater will not work unless the enclosure is wired correctly for 120V operation. The AC input to the enclosure must be tied into line 1 and line 2 for 120V operation. If the heater or stir fan is not working still, then you must check the relay for damage. The heater relay is located at the top left front of the enclosure. You must take off the small cover on the outside of the enclosure to access the relay.
The sir fan relay is located on IOB 4, on the middle right side of the enclosure on the wall. If the relay shows no damage, and the stir-fan or heater are still not coming on it is recommended you replace the relay before replacing the stir-fan or heater.
Remember to go back and change the Digital Outputs back to automatic when done testing.