"Cyclical reference detected" on calculation task

I'm trying to cumulate the results from each "Operating time" on each thermostat.

Each of them calculates the time the floor heating is active.

I'm then getting "Cyclical reference" from the calculation task.

Anyone know why this happens ?

I don't have it all the time, for example I had floor heating on 3 rooms activated for 10h, but one of the rooms activated for 6h of them, and when that room activated it started triggering those alerts, and when all rooms stopped heating up, it stopped triggering the errors.

To resume:
- Each thermostat has an Operating time task
- A Calculation task (A) is adding up all the values returned by each Operating time
- Every 24h I'm saving that calculated value in a Analog Log (C)

- Then I have another Calculation task (B) which get the values from (A) and removes the Day Max from (C)
- Then another Analog Log (D) gets the value from (B) every 5 minutes and show it in a graph 

And ComfortClick is triggering alerts about Cyclical references thrown by (A)