Herpstat power issues

[Eric Alan]

Mine fluctuates all the time anywhere from 100% to 0% for my RHP depending on the power need. That's normal for a proportional thermostat. You really only need to worry if it stays at 100% for hours and hours and hours which will probably mean your heat source is too small to achieve the temp you have it set for and you will need to up the heat source.

Or your probe has moved and your heat source is unknowingly trying to raise the temperature of the entire room/enclosure.