It is still snowing outside but the snow is no longer being melted off my roof.
Moisture sensor placement is crucial to the proper operation of your unit. If you install it in an area prone to snow slides, the sensor can get buried.
The sensor head runs hot enough to melt the snow above it for an inch or so, but if enough snow piles on top of it, there will be an igloo effect that will prevent snowfall from reaching the sensor grid.
A good rule of thumb is if you are installing the moisture sensor in the gutter, place it below one of the heat cable loops to try to help make sure whatever is coming down the roof gets melted before it runs onto the moisture sensor.
It helps keep the sensor from getting buried.