Temp control chiller switching

[Aquagen]

I am trying to get my head around temp control just to save wear and tear on my chiller cycling on and off.
Desired temp 25.2c. I want chiller to turn on at 25.6, off at 25.2. Heater on at 24.8, off at 25.2

Currently the chiller is on and off every 5 mins and maintaining 25.3, I'd just prefer a longer run time on the chiller so it's not short cycling

 

[Ditto]

This is because of your Hysteresis being only .2 which means if the the temp is above 25.1 is going to turn on and stay on till it gets to 25.0 and rinse and repeat.

If you want a larger gap for example 25.6 you want it on and then off at 25..0 then make your hysteresis 1.2. One half of it will be .6 which means 25.6 will turn on at 25.6 remain on till 25.0. (That based on the nominal value in the picture above)

If your nominal is 25.2 your hysteresis would be .800 This means it turns on at 25.6 (25.2 + 1/2 the value of Hysteresis value) and turns off at 25.0 for cooling. Which I believe is what you want your desired temp to be

The reverse of this for heating would be on at 24.8 and off at 25.2 if the heating option is used.

Hope this helps

 

[Aquagen]

So this is what I can find in the manual.
But I'll increase the hysterisis to 0.5 and see what happens. Should I change the cooling difference either to 0 or to a larger number?


The adjusted hysteresis also depends on when the cooling is active. The
switching-on point of the cooling also depends on the cooling difference
(see also Sensors-> Cooling difference) and can be calculated as follows:
T = nominal temperature + 5/6 * hysteresis + cooling difference
With a hysteresis of 0.2 °C, this results: T = Nominal temperature + 0.167 °C
+ cooling difference.

5.11 Cooling Difference
(Only with temperature sensor)
If the cooling is not to be active within the usual control (observing the nominal temperature
with regard to the hysteresis), but only delayed, the Cooling difference can be used to
determine how far the temperature must exceed the set temperature until the cooling
becomes active.
Values can be set between 0.0 °C (no delay, cooling is active immediately when the nominal
temperature is exceeded) and 5.0 °C (maximum delay, cooling is active when the nominal
temperature is exceeded by 5.0 °C). The cooling difference also affects the alarm monitoring.

 

[Ditto]

You can if you want for my chiller it is at 0, as I did not need the delay, but have seen people add the delay if they believe it still switching on to much.

 

[Aquagen]

I'll run at 0 cooling difference for today. Summer here so won't be able to see how it affects heating for a few months