Drywell sensors are 5/16" in
diameter. This is the most common sensor used by Gatsby.
Wetwell sensors are 3/8" in diameter and is less common.
On the LEFT see an older "wet well" sensor and
housing. You can see the tip end of the sensor and usually can touch
it. Water actually touches the sensor so its always stainless steel.
This housing is no longer available. The replacement is
a drywell housing that will accommodate the larger
diameter sensor. (black)
On the RIGHT is a "dry well" sensor
and housing. You might be able to see the sensor but its in the
housing. So the water flows around the sensor but never touches. The
sensor can be black plastic or stainless steel. Replacement housing