The pressure in the system changes with the temperature of the water, since the LEAKSHIELD is extremely sensitive, this results in a constant up and down.

If you had a water leak in your circuit you would notice it immediately, there would be so much air sucked into the system that the LEAKSHIELD could not hold the pressure, small air leaks are normal and can hardly be prevented with water cooling hardware, because it is designed for water tightness.

If your LEAKSHIELD is not pumping too often everything is ok, according to Aquasuite it should pump less than 30 seconds per day.

Larger air leaks can be detected by air bubbles forming in the system overnight, if the LEAKSHIELD is in shield mode and has power. Since the pump is not running, you can then estimate quite well in the morning where the leak can be.

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I look at the average pressure leak rate, I see the same with negative numbers when its well-sealed.