sell all of them on ebay and get a ranco or johnsons.

never have to worry again!*

*as a note, there are a lot of people who can use the zoomed stuff well.. they NEVER worked for me and i had one for a few months. the temps never stabilized because my room temps swung like crazy. With a thermostat with a digital read out and temperature setting (ie, NOT a zoomed thermostat or rheostat), i have never had to worry since. I replaced my zoomed with a johnsons, and now have a helix. The johnsons control is a backup thermostat now.