Needing help - Heater and chiller code


New member
Fallback OFF
If Temp < RT+-0.3 Then ON
If Temp > RT+-0.3 Then OFF
Min Time 002:00 Then OFF

I have no hysterisis on this program, just the Min Time statement that minimizes rapid on/offs around the set point. I have the built in thermostat set to 78ish (as a safety) and the heater plugged in to a solid state EB8 outlet (1-3 or 5-7). Te heater will come on when the temp is 0.3 degrees below the RT temp (note the plus minus (+-) before the offset) and turn off if above 0.3 below RT.

Fallback OFF
If Temp > RT+0.5 Then ON
If Temp < RT+0.2 Then OFF
Min Time 010:00 Then ON

Similar setup for the chiller except the ON range is wider. I also have the Chiller thermostat set to ~76 degrees as a safe guard.

Note that the Heater and Chiller ON temps are .5 degrees apart, preventing them from competing with each other.
Last edited: