If you purchase a new thermostat to replace an older model, make sure that you do not just throw the old thermostat in the trash. If your new thermostat is replacing a thermostat that contains mercury in a sealed tube, it can not be thrown into the regular garbage. Contact your local waste management authority for instructions on how to properly dispose of the thermostat.
Honeywell thermostats, Robertshaw thermostats and White Rodgers thermostats can be found at www.supplyhouse.com