Where I work we have literately hundreds of thermostats controlling single stage residential water source heat pumps. In 1990 at start-up of the facility we had Robertshaw snap acting thermostats. When we started having problems with them ( bi-metal inaccuracy, dirty contacts, etc. ) we began to switch over to the newer Honeywell T8775C1005 Digital Round. They are easy, large enough t see and when the display flips from set point to rom temp. the residents dn't know that it may be a few degrees off :) After a short time they fail at random (very annoying for me) I need a thermostat that is easy to see...easy to operate...accurate ( the bi-metal ones never reflect actual temperature) and will last a god amount of time (is 5 years reasonable?) I deal with the elderly and they need all of the above and I need one that I don't have to change all the time.