Just discovered this neat thermostat for water well freeze protection. It's called a Thermo-Cube. It is a duplex outlet that plugs into a standarg 110v outlet. Turns on at 35 degrees and off at 45 degrees (max. 15 amps).You can find them at www.aquaticeco.com for about $15. Probably been around a long time but new to me--thought I would share.