What is a potential consequence of using too much reset when tuning a control loop?

Using too much reset, also referred to as integral action in a control loop, can lead to decreased stability. When you increase the reset (integral gain), the controller becomes more aggressive in trying to eliminate the error over time. However, if the reset is set too high, it can cause the system to react too strongly to any error, leading to overshoot and excessive oscillations. This behavior can destabilize the control loop, making it harder to maintain a stable process.

While it's true that increasing reset may also impact return time to set point and the period of oscillation, these effects can be secondary and can vary based on the specific design and dynamics of the control loop. The primary and most concerning consequence of too much reset is indeed a degradation in system stability, leading to potentially erratic and unpredictable system behavior.