I had my incubator full when incubating the weak clutch with the eye problems. all the others were perfectly fine. I do use the herpstat nd thermostat which has high and low level alarms. which is one of the reasons I went with the nd. knowing I would never use the night drop feature on it which is what the nd stands for. but it has so many other features that I was looking for. using this thermostat for a few years and no regrets on buying it. good luck with the clown clutch, don