I assume you have very little air in the reservoir, the less air volume the faster the pressure changes.
Since every change in water temperature also changes the pressure in the loop, this can lead to alarms.
The sensors of the LEAKSHIELD are extremely sensitive, you can see this if you look at the diagrams on the LEAKSHIELD overview page.
As a solution you can increase the air volume in the reservoir, at least 100 ml is recommended, more is better.
If this is not the problem, much more information would be helpful
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