Integral sensor having strange jumps

[gerione (Gerald Kettlgruber)]

I am tracking the heat provided by the heat pump.
Heat is calculated with returning / leaving water temperatures and flows.
Sometimes, when the heat pump is not running for some time the heat integral sensor is having jumps. Although I set the max sub interval to 30sec.
The setup is the following:

Here a jump (upper graph is the intergral sensor, below the signal of the heat):

Any guess, on why there is such a big jump all of a sudden?

[karwosts]

Use left mode. You’re getting a jump because you’re using trapezoidal calculation. That does not work well with sensors which stay 0 for long periods of time.